petapoco-SQLServer模型增加注释

petapoco是个基于T4模板的轻量级ORM，好用效率高，具体介绍略了

获取注释基本原理是调用数据库::fn_listextendedproperty函数，获取扩展属性MS_Description

technet参考资料：sys.fn_listextendedproperty (Transact-SQL)

直接上代码

首先是PetaPoco.Core.ttinclude

106行原始：

...
public string SequenceName;
    public bool Ignore;
...

新建Description字段，这个是表的注释

...
    public string SequenceName;
    public bool Ignore;
    public string Description;
...

140行原始：

...
    public bool IsAutoIncrement;
    public bool Ignore;
...

新建Description字段，这个是列的注释

...
    public bool IsAutoIncrement;
    public bool Ignore;
    public string Description;
...

517行SqlServerSchemaReader.ReadSchema方法，原始：

...
foreach (var tbl in result)
        {
            tbl.Columns=LoadColumns(tbl);

            // Mark the primary key
            string PrimaryKey=GetPK(tbl.Name);
            var pkColumn=tbl.Columns.SingleOrDefault(x=>x.Name.ToLower().Trim()==PrimaryKey.ToLower().Trim());
            if(pkColumn!=null)
            {
                pkColumn.IsPK=true;
            }
        }
...

修改后，调用函数获取表的注释：

...
        foreach (var tbl in result)
        {
            using(var cmdDesc=_factory.CreateCommand())
            {
                cmdDesc.Connection=connection;
                cmdDesc.CommandText=TABLE_DESC_SQL;

                DbParameter p = null;

                p = cmdDesc.CreateParameter();
                p.ParameterName = "@schema";
                p.Value=tbl.Schema;
                cmdDesc.Parameters.Add(p);

                p = cmdDesc.CreateParameter();
                p.ParameterName = "@table";
                p.Value=tbl.Name;
                cmdDesc.Parameters.Add(p);

                using (var rdrDesc=cmdDesc.ExecuteReader())
                {
                    if(rdrDesc.Read())
                        tbl.Description=rdrDesc["value"].ToString();
                }
            }
...

572行插入新的代码，获取每一列的注释：

...
            foreach (var col in result)
            {
                using(var cmdDesc=_factory.CreateCommand())
                {
                    cmdDesc.Connection=_connection;
                    cmdDesc.CommandText=COLUMN_DESC_SQL;

                    DbParameter pDesc = null;

                    pDesc = cmdDesc.CreateParameter();
                    pDesc.ParameterName = "@schema";
                    pDesc.Value=tbl.Schema;
                    cmdDesc.Parameters.Add(pDesc);

                    pDesc = cmdDesc.CreateParameter();
                    pDesc.ParameterName = "@table";
                    pDesc.Value=tbl.Name;
                    cmdDesc.Parameters.Add(pDesc);

                    pDesc = cmdDesc.CreateParameter();
                    pDesc.ParameterName = "@column";
                    pDesc.Value=col.Name;
                    cmdDesc.Parameters.Add(pDesc);
                    using (var rdrDesc=cmdDesc.ExecuteReader())
                    {
                        if(rdrDesc.Read())
                            col.Description=rdrDesc["value"].ToString();
                    }
                }
            }
...

672行插入新的代码，存储调用函数的sql语句：

...
    const string TABLE_DESC_SQL=@"SELECT value FROM ::fn_listextendedproperty('MS_Description', 'user', @schema, 'table', @table, null, null)";
    const string COLUMN_DESC_SQL=@"SELECT value FROM ::fn_listextendedproperty('MS_Description', 'user', @schema, 'table', @table, 'column', @column)";
...

附完整PetaPoco.Core.ttinclude：

 <#@ template language="C#v3.5" hostspecific="True" #>
 <#@ assembly name="EnvDTE" #>
 <#@ assembly name="System.Core.dll" #>
 <#@ assembly name="System.Data" #>
 <#@ assembly name="System.Xml" #>
 <#@ assembly name="System.Configuration" #>
 <#@ assembly name="System.Windows.Forms" #>
 <#@ import namespace="System.Collections.Generic" #>
 <#@ import namespace="System.Data" #>
 <#@ import namespace="System.Data.SqlClient" #>
 <#@ import namespace="System.Data.Common" #>
 <#@ import namespace="System.Diagnostics" #>
 <#@ import namespace="System.Globalization" #>
 <#@ import namespace="System.IO" #>
 <#@ import namespace="System.Linq" #>
 <#@ import namespace="System.Text" #>
 <#@ import namespace="System.Text.RegularExpressions" #>
 <#@ import namespace="System.Configuration" #>
 <#@ import namespace="System.Windows.Forms" #>
 <#+

 /*
  This code is part of the PetaPoco project (http://www.toptensoftware.com/petapoco).
  It is based on the SubSonic T4 templates but has been considerably re-organized and reduced

  -----------------------------------------------------------------------------------------

  This template can read minimal schema information from the following databases:

     * SQL Server
     * SQL Server CE
     * MySQL
     * PostGreSQL
     * Oracle

  For connection and provider settings the template will look for the web.config or app.config file of the
  containing Visual Studio project.  It will not however read DbProvider settings from this file.

  In order to work, the appropriate driver must be registered in the system machine.config file.  If you're
  using Visual Studio 2010 the file you want is here:

     C:\Windows\Microsoft.NET\Framework\v4.0.30319\Config\machine.config

  After making changes to machine.config you will also need to restart Visual Studio.

  Here's a typical set of entries that might help if you're stuck:

     <system.data>
         <DbProviderFactories>
             <add name="Odbc Data Provider" invariant="System.Data.Odbc" description=".Net Framework Data Provider for Odbc" type="System.Data.Odbc.OdbcFactory, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
             <add name="OleDb Data Provider" invariant="System.Data.OleDb" description=".Net Framework Data Provider for OleDb" type="System.Data.OleDb.OleDbFactory, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
             <add name="OracleClient Data Provider" invariant="System.Data.OracleClient" description=".Net Framework Data Provider for Oracle" type="System.Data.OracleClient.OracleClientFactory, System.Data.OracleClient, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
             <add name="SqlClient Data Provider" invariant="System.Data.SqlClient" description=".Net Framework Data Provider for SqlServer" type="System.Data.SqlClient.SqlClientFactory, System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089"/>
             <add name="MySQL Data Provider" invariant="MySql.Data.MySqlClient" description=".Net Framework Data Provider for MySQL" type="MySql.Data.MySqlClient.MySqlClientFactory, MySql.Data, Version=6.3.4.0, Culture=neutral, PublicKeyToken=c5687fc88969c44d"/>
             <add name="Microsoft SQL Server Compact Data Provider" invariant="System.Data.SqlServerCe.3.5" description=".NET Framework Data Provider for Microsoft SQL Server Compact" type="System.Data.SqlServerCe.SqlCeProviderFactory, System.Data.SqlServerCe, Version=3.5.1.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"/><add name="Microsoft SQL Server Compact Data Provider 4.0" invariant="System.Data.SqlServerCe.4.0" description=".NET Framework Data Provider for Microsoft SQL Server Compact" type="System.Data.SqlServerCe.SqlCeProviderFactory, System.Data.SqlServerCe, Version=4.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"/>
             <add name="Npgsql Data Provider" invariant="Npgsql" support="FF" description=".Net Framework Data Provider for Postgresql Server" type="Npgsql.NpgsqlFactory, Npgsql, Version=2.0.11.91, Culture=neutral, PublicKeyToken=5d8b90d52f46fda7" />
         </DbProviderFactories>
     </system.data>

  Also, the providers and their dependencies need to be installed to GAC.  

  Eg; this is how I installed the drivers for PostgreSQL

      gacutil /i Npgsql.dll
      gacutil /i Mono.Security.dll

  -----------------------------------------------------------------------------------------

  SubSonic - http://subsonicproject.com

  The contents of this file are subject to the New BSD
  License (the "License"); you may not use this file
  except in compliance with the License. You may obtain a copy of
  the License at http://www.opensource.org/licenses/bsd-license.php

  Software distributed under the License is distributed on an
  "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
  implied. See the License for the specific language governing
  rights and limitations under the License.
 */

 string ConnectionStringName = "";
 string Namespace = "";
 string RepoName = "";
 string ClassPrefix = "";
 string ClassSuffix = "";
 string SchemaName = null;
 bool IncludeViews = false;
 bool GenerateOperations = false;
 bool GenerateCommon = true;
 bool GeneratePocos = true;
 bool ExplicitColumns = true;
 bool TrackModifiedColumns = false;
 string[] ExcludePrefix = new string[] {};

 public class Table
 {
     public List<Column> Columns;
     public string Name;
     public string Schema;
     public bool IsView;
     public string CleanName;
     public string ClassName;
     public string SequenceName;
     public bool Ignore;
     public string Description;

     public Column PK
     {
         get
         {
             return this.Columns.SingleOrDefault(x=>x.IsPK);
         }
     }

     public Column GetColumn(string columnName)
     {
         return Columns.Single(x=>string.Compare(x.Name, columnName, true)==);
     }

     public Column this[string columnName]
     {
         get
         {
             return GetColumn(columnName);
         }
     }

 }

 public class Column
 {
     public string Name;
     public string PropertyName;
     public string PropertyType;
     public bool IsPK;
     public bool IsNullable;
     public bool IsAutoIncrement;
     public bool Ignore;
     public string Description;
 }

 public class Tables : List<Table>
 {
     public Tables()
     {
     }

     public Table GetTable(string tableName)
     {
         return this.Single(x=>string.Compare(x.Name, tableName, true)==);
     }

     public Table this[string tableName]
     {
         get
         {
             return GetTable(tableName);
         }
     }

 }

 static Regex rxCleanUp = new Regex(@"[^\w\d_]", RegexOptions.Compiled);

 static string[] cs_keywords = { "abstract", "event", "new", "struct", "as", "explicit", "null",
      "switch", "base", "extern", "object", "this", "bool", "false", "operator", "throw",
      "break", "finally", "out", "true", "byte", "fixed", "override", "try", "case", "float",
      "params", "typeof", "catch", "for", "private", "uint", "char", "foreach", "protected",
      "ulong", "checked", "goto", "public", "unchecked", "class", "if", "readonly", "unsafe",
      "const", "implicit", "ref", "ushort", "continue", "in", "return", "using", "decimal",
      "int", "sbyte", "virtual", "default", "interface", "sealed", "volatile", "delegate",
      "internal", "short", "void", "do", "is", "sizeof", "while", "double", "lock",
      "stackalloc", "else", "long", "static", "enum", "namespace", "string" };

 static Func<string, string> CleanUp = (str) =>
 {
     str = rxCleanUp.Replace(str, "_");

     if (char.IsDigit(str[]) || cs_keywords.Contains(str))
         str = "@" + str;

     return str;
 };

 string CheckNullable(Column col)
 {
     string result="";
     if(col.IsNullable &&
         col.PropertyType !="byte[]" &&
         col.PropertyType !="string" &&
         col.PropertyType !="Microsoft.SqlServer.Types.SqlGeography" &&
         col.PropertyType !="Microsoft.SqlServer.Types.SqlGeometry"
         )
         result="?";
     return result;
 }

 string GetConnectionString(ref string connectionStringName, out string providerName)
 {
     var _CurrentProject = GetCurrentProject();

     providerName=null;

     string result="";
     ExeConfigurationFileMap configFile = new ExeConfigurationFileMap();
     configFile.ExeConfigFilename = GetConfigPath();

     if (string.IsNullOrEmpty(configFile.ExeConfigFilename))
         throw new ArgumentNullException("The project does not contain App.config or Web.config file.");

     var config = System.Configuration.ConfigurationManager.OpenMappedExeConfiguration(configFile, ConfigurationUserLevel.None);
     var connSection=config.ConnectionStrings;

     //if the connectionString is empty - which is the defauls
     //look for count-1 - this is the last connection string
     //and takes into account AppServices and LocalSqlServer
     if(string.IsNullOrEmpty(connectionStringName))
     {
         if(connSection.ConnectionStrings.Count>)
         {
             connectionStringName = connSection.ConnectionStrings[connSection.ConnectionStrings.Count-].Name;
             result=connSection.ConnectionStrings[connSection.ConnectionStrings.Count-].ConnectionString;
             providerName=connSection.ConnectionStrings[connSection.ConnectionStrings.Count-].ProviderName;
         }
     }
     else
     {
         try
         {
             result=connSection.ConnectionStrings[connectionStringName].ConnectionString;
             providerName=connSection.ConnectionStrings[connectionStringName].ProviderName;
         }
         catch
         {
             result="There is no connection string name called '"+connectionStringName+"'";
         }
     }

 //    if (String.IsNullOrEmpty(providerName))
 //        providerName="System.Data.SqlClient";

     return result;
 }

 string _connectionString="";
 string _providerName="";

 void InitConnectionString()
 {
     if(String.IsNullOrEmpty(_connectionString))
     {
         _connectionString=GetConnectionString(ref ConnectionStringName, out _providerName);

         if(_connectionString.Contains("|DataDirectory|"))
         {
             //have to replace it
             string dataFilePath=GetDataDirectory();
             _connectionString=_connectionString.Replace("|DataDirectory|",dataFilePath);
         }
     }
 }

 public string ConnectionString
 {
     get
     {
         InitConnectionString();
         return _connectionString;
     }
 }

 public string ProviderName
 {
     get
     {
         InitConnectionString();
         return _providerName;
     }
 }

 public EnvDTE.Project GetCurrentProject()  {

     IServiceProvider _ServiceProvider = (IServiceProvider)Host;
     if (_ServiceProvider == null)
         throw new Exception("Host property returned unexpected value (null)");

     EnvDTE.DTE dte = (EnvDTE.DTE)_ServiceProvider.GetService(typeof(EnvDTE.DTE));
     if (dte == null)
         throw new Exception("Unable to retrieve EnvDTE.DTE");

     Array activeSolutionProjects = (Array)dte.ActiveSolutionProjects;
     if (activeSolutionProjects == null)
         throw new Exception("DTE.ActiveSolutionProjects returned null");

     EnvDTE.Project dteProject = (EnvDTE.Project)activeSolutionProjects.GetValue();
     if (dteProject == null)
         throw new Exception("DTE.ActiveSolutionProjects[0] returned null");

     return dteProject;

 }

 private string GetProjectPath()
 {
     EnvDTE.Project project = GetCurrentProject();
     System.IO.FileInfo info = new System.IO.FileInfo(project.FullName);
     return info.Directory.FullName;
 }

 private string GetConfigPath()
 {
     EnvDTE.Project project = GetCurrentProject();
     foreach (EnvDTE.ProjectItem item in project.ProjectItems)
     {
         // if it is the app.config file, then open it up
         if (item.Name.Equals("App.config",StringComparison.InvariantCultureIgnoreCase) || item.Name.Equals("Web.config",StringComparison.InvariantCultureIgnoreCase))
             return GetProjectPath() + "\\" + item.Name;
     }
     return String.Empty;
 }

 public string GetDataDirectory()
 {
     EnvDTE.Project project=GetCurrentProject();
     return System.IO.Path.GetDirectoryName(project.FileName)+"\\App_Data\\";
 }

 static string zap_password(string connectionString)
 {
     var rx = new Regex("password=.*;", RegexOptions.Singleline | RegexOptions.Multiline | RegexOptions.IgnoreCase);
     return rx.Replace(connectionString, "password=**zapped**;");
 }

 Tables LoadTables()
 {
     InitConnectionString();

     WriteLine("// This file was automatically generated by the PetaPoco T4 Template");
     WriteLine("// Do not make changes directly to this file - edit the template instead");
     WriteLine("// ");
     WriteLine("// The following connection settings were used to generate this file");
     WriteLine("// ");
     WriteLine("//     Connection String Name: `{0}`", ConnectionStringName);
     WriteLine("//     Provider:               `{0}`", ProviderName);
     WriteLine("//     Connection String:      `{0}`", zap_password(ConnectionString));
     WriteLine("//     Schema:                 `{0}`", SchemaName);
     WriteLine("//     Include Views:          `{0}`", IncludeViews);
     WriteLine("");

     DbProviderFactory _factory;
     try
     {
         _factory = DbProviderFactories.GetFactory(ProviderName);
     }
     catch (Exception x)
     {
         var error=x.Message.Replace("\r\n", "\n").Replace("\n", " ");
         Warning(string.Format("Failed to load provider `{0}` - {1}", ProviderName, error));
         WriteLine("");
         WriteLine("// -----------------------------------------------------------------------------------------");
         WriteLine("// Failed to load provider `{0}` - {1}", ProviderName, error);
         WriteLine("// -----------------------------------------------------------------------------------------");
         WriteLine("");
         return new Tables();
     }

     try
     {
         Tables result;
         using(var conn=_factory.CreateConnection())
         {
             conn.ConnectionString=ConnectionString;
             conn.Open();

             SchemaReader reader=null;

             if (_factory.GetType().Name == "MySqlClientFactory")
             {
                 // MySql
                 reader=new MySqlSchemaReader();
             }
             else if (_factory.GetType().Name == "SqlCeProviderFactory")
             {
                 // SQL CE
                 reader=new SqlServerCeSchemaReader();
             }
             else if (_factory.GetType().Name == "NpgsqlFactory")
             {
                 // PostgreSQL
                 reader=new PostGreSqlSchemaReader();
             }
             else if (_factory.GetType().Name == "OracleClientFactory")
             {
                 // Oracle
                 reader=new OracleSchemaReader();
             }
             else
             {
                 // Assume SQL Server
                 reader=new SqlServerSchemaReader();
             }

             reader.outer=this;
             result=reader.ReadSchema(conn, _factory);

             // Remove unrequired tables/views
             for (int i=result.Count-; i>=; i--)
             {
                 if (SchemaName!=null && string.Compare(result[i].Schema, SchemaName, true)!=)
                 {
                     result.RemoveAt(i);
                     continue;
                 }
                 if (!IncludeViews && result[i].IsView)
                 {
                     result.RemoveAt(i);
                     continue;
                 }
                 if(StartsWithAny(result[i].ClassName, ExcludePrefix)) {
                     result.RemoveAt(i);
                     continue;
                 }
             }

             conn.Close();

             var rxClean = new Regex("^(Equals|GetHashCode|GetType|ToString|repo|Save|IsNew|Insert|Update|Delete|Exists|SingleOrDefault|Single|First|FirstOrDefault|Fetch|Page|Query)$");
             foreach (var t in result)
             {
                 t.ClassName = ClassPrefix + t.ClassName + ClassSuffix;
                 foreach (var c in t.Columns)
                 {
                     c.PropertyName = rxClean.Replace(c.PropertyName, "_$1");

                     // Make sure property name doesn't clash with class name
                     if (c.PropertyName == t.ClassName)
                         c.PropertyName = "_" + c.PropertyName;
                 }
             }

             return result;
         }
     }
     catch (Exception x)
     {
         var error=x.Message.Replace("\r\n", "\n").Replace("\n", " ");
         Warning(string.Format("Failed to read database schema - {0}", error));
         WriteLine("");
         WriteLine("// -----------------------------------------------------------------------------------------");
         WriteLine("// Failed to read database schema - {0}", error);
         WriteLine("// -----------------------------------------------------------------------------------------");
         WriteLine("");
         return new Tables();
     }

 }

 bool StartsWithAny(string s, IEnumerable<string> items)
 {
     if (s == null)
         return false;

     return items.Any(i => s.StartsWith(i));
 }

 abstract class SchemaReader
 {
     public abstract Tables ReadSchema(DbConnection connection, DbProviderFactory factory);
     public GeneratedTextTransformation outer;
     public void WriteLine(string o)
     {
         outer.WriteLine(o);
     }

 }

 class SqlServerSchemaReader : SchemaReader
 {
     // SchemaReader.ReadSchema
     public override Tables ReadSchema(DbConnection connection, DbProviderFactory factory)
     {
         var result=new Tables();

         _connection=connection;
         _factory=factory;

         //pull the tables in a reader
         using(var cmd=_factory.CreateCommand())
         {
             cmd.Connection=connection;
             cmd.CommandText=TABLE_SQL;
             using (var rdr=cmd.ExecuteReader())
             {
                 while(rdr.Read())
                 {
                     Table tbl=new Table();
                     tbl.Name=rdr["TABLE_NAME"].ToString();
                     tbl.Schema=rdr["TABLE_SCHEMA"].ToString();
                     tbl.IsView=string.Compare(rdr["TABLE_TYPE"].ToString(), "View", true)==;
                     tbl.CleanName=CleanUp(tbl.Name);
                     tbl.ClassName=Inflector.MakeSingular(tbl.CleanName);
                     result.Add(tbl);
                 }
             }
         }
         foreach (var tbl in result)
         {
             using(var cmdDesc=_factory.CreateCommand())
             {
                 cmdDesc.Connection=connection;
                 cmdDesc.CommandText=TABLE_DESC_SQL;

                 DbParameter p = null;

                 p = cmdDesc.CreateParameter();
                 p.ParameterName = "@schema";
                 p.Value=tbl.Schema;
                 cmdDesc.Parameters.Add(p);

                 p = cmdDesc.CreateParameter();
                 p.ParameterName = "@table";
                 p.Value=tbl.Name;
                 cmdDesc.Parameters.Add(p);

                 using (var rdrDesc=cmdDesc.ExecuteReader())
                 {
                     if(rdrDesc.Read())
                         tbl.Description=rdrDesc["value"].ToString();
                 }
             }

             tbl.Columns=LoadColumns(tbl);

             // Mark the primary key
             string PrimaryKey=GetPK(tbl.Name);
             var pkColumn=tbl.Columns.SingleOrDefault(x=>x.Name.ToLower().Trim()==PrimaryKey.ToLower().Trim());
             if(pkColumn!=null)
             {
                 pkColumn.IsPK=true;
             }
         }

         return result;
     }

     DbConnection _connection;
     DbProviderFactory _factory;

     List<Column> LoadColumns(Table tbl)
     {

         using (var cmd=_factory.CreateCommand())
         {
             cmd.Connection=_connection;
             cmd.CommandText=COLUMN_SQL;

             var p = cmd.CreateParameter();
             p.ParameterName = "@tableName";
             p.Value=tbl.Name;
             cmd.Parameters.Add(p);

             p = cmd.CreateParameter();
             p.ParameterName = "@schemaName";
             p.Value=tbl.Schema;
             cmd.Parameters.Add(p);

             var result=new List<Column>();
             using (IDataReader rdr=cmd.ExecuteReader())
             {
                 while(rdr.Read())
                 {
                     Column col=new Column();
                     col.Name=rdr["ColumnName"].ToString();
                     col.PropertyName=CleanUp(col.Name);
                     col.PropertyType=GetPropertyType(rdr["DataType"].ToString());
                     col.IsNullable=rdr["IsNullable"].ToString()=="YES";
                     col.IsAutoIncrement=((int)rdr["IsIdentity"])== ||
                             (!DBNull.Value.Equals(rdr["DefaultSetting"]) && ((string)rdr["DefaultSetting"] == "(newsequentialid())" ||
                             (string)rdr["DefaultSetting"] == "(newid())"));
                     result.Add(col);
                 }
             }
             foreach (var col in result)
             {
                 using(var cmdDesc=_factory.CreateCommand())
                 {
                     cmdDesc.Connection=_connection;
                     cmdDesc.CommandText=COLUMN_DESC_SQL;

                     DbParameter pDesc = null;

                     pDesc = cmdDesc.CreateParameter();
                     pDesc.ParameterName = "@schema";
                     pDesc.Value=tbl.Schema;
                     cmdDesc.Parameters.Add(pDesc);

                     pDesc = cmdDesc.CreateParameter();
                     pDesc.ParameterName = "@table";
                     pDesc.Value=tbl.Name;
                     cmdDesc.Parameters.Add(pDesc);

                     pDesc = cmdDesc.CreateParameter();
                     pDesc.ParameterName = "@column";
                     pDesc.Value=col.Name;
                     cmdDesc.Parameters.Add(pDesc);
                     using (var rdrDesc=cmdDesc.ExecuteReader())
                     {
                         if(rdrDesc.Read())
                             col.Description=rdrDesc["value"].ToString();
                     }
                 }
             }
             return result;
         }
     }

     string GetPK(string table){

         string sql=@"SELECT c.name AS ColumnName
                 FROM sys.indexes AS i
                 INNER JOIN sys.index_columns AS ic ON i.object_id = ic.object_id AND i.index_id = ic.index_id
                 INNER JOIN sys.objects AS o ON i.object_id = o.object_id
                 LEFT OUTER JOIN sys.columns AS c ON ic.object_id = c.object_id AND c.column_id = ic.column_id
                 WHERE (i.is_primary_key = 1) AND (o.name = @tableName)";

         using (var cmd=_factory.CreateCommand())
         {
             cmd.Connection=_connection;
             cmd.CommandText=sql;

             var p = cmd.CreateParameter();
             p.ParameterName = "@tableName";
             p.Value=table;
             cmd.Parameters.Add(p);

             var result=cmd.ExecuteScalar();

             if(result!=null)
                 return result.ToString();
         }             

         return "";
     }

     string GetPropertyType(string sqlType)
     {
         string sysType="string";
         switch (sqlType)
         {
             case "bigint":
                 sysType = "long";
                 break;
             case "smallint":
                 sysType= "short";
                 break;
             case "int":
                 sysType= "int";
                 break;
             case "uniqueidentifier":
                 sysType=  "Guid";
                  break;
             case "smalldatetime":
             case "datetime":
             case "datetime2":
             case "date":
             case "time":
                 sysType=  "DateTime";
                   break;
             case "datetimeoffset":
                 sysType = "DateTimeOffset";
                 break;
               case "float":
                 sysType="double";
                 break;
             case "real":
                 sysType="float";
                 break;
             case "numeric":
             case "smallmoney":
             case "decimal":
             case "money":
                 sysType=  "decimal";
                  break;
             case "tinyint":
                 sysType = "byte";
                 break;
             case "bit":
                 sysType=  "bool";
                    break;
             case "image":
             case "binary":
             case "varbinary":
             case "timestamp":
                 sysType=  "byte[]";
                  break;
             case "geography":
                 sysType = "Microsoft.SqlServer.Types.SqlGeography";
                 break;
             case "geometry":
                 sysType = "Microsoft.SqlServer.Types.SqlGeometry";
                 break;
         }
         return sysType;
     }

     const string TABLE_SQL=@"SELECT *
         FROM  INFORMATION_SCHEMA.TABLES
         WHERE TABLE_TYPE='BASE TABLE' OR TABLE_TYPE='VIEW'
         ORDER BY TABLE_SCHEMA,TABLE_TYPE,TABLE_NAME";

     const string TABLE_DESC_SQL=@"SELECT value FROM ::fn_listextendedproperty('MS_Description', 'user', @schema, 'table', @table, null, null)";

     const string COLUMN_SQL=@"SELECT
             TABLE_CATALOG AS [Database],
             TABLE_SCHEMA AS Owner,
             TABLE_NAME AS TableName,
             COLUMN_NAME AS ColumnName,
             ORDINAL_POSITION AS OrdinalPosition,
             COLUMN_DEFAULT AS DefaultSetting,
             IS_NULLABLE AS IsNullable, DATA_TYPE AS DataType,
             CHARACTER_MAXIMUM_LENGTH AS MaxLength,
             DATETIME_PRECISION AS DatePrecision,
             COLUMNPROPERTY(object_id('[' + TABLE_SCHEMA + '].[' + TABLE_NAME + ']'), COLUMN_NAME, 'IsIdentity') AS IsIdentity,
             COLUMNPROPERTY(object_id('[' + TABLE_SCHEMA + '].[' + TABLE_NAME + ']'), COLUMN_NAME, 'IsComputed') as IsComputed
         FROM  INFORMATION_SCHEMA.COLUMNS
         WHERE TABLE_NAME=@tableName AND TABLE_SCHEMA=@schemaName
         ORDER BY OrdinalPosition ASC";

     const string COLUMN_DESC_SQL=@"SELECT value FROM ::fn_listextendedproperty('MS_Description', 'user', @schema, 'table', @table, 'column', @column)";
 }

 class SqlServerCeSchemaReader : SchemaReader
 {
     // SchemaReader.ReadSchema
     public override Tables ReadSchema(DbConnection connection, DbProviderFactory factory)
     {
         var result=new Tables();

         _connection=connection;
         _factory=factory;

         var cmd=_factory.CreateCommand();
         cmd.Connection=connection;
         cmd.CommandText=TABLE_SQL;

         //pull the tables in a reader
         using(cmd)
         {
             using (var rdr=cmd.ExecuteReader())
             {
                 while(rdr.Read())
                 {
                     Table tbl=new Table();
                     tbl.Name=rdr["TABLE_NAME"].ToString();
                     tbl.CleanName=CleanUp(tbl.Name);
                     tbl.ClassName=Inflector.MakeSingular(tbl.CleanName);
                     tbl.Schema=null;
                     tbl.IsView=false;
                     result.Add(tbl);
                 }
             }
         }

         foreach (var tbl in result)
         {
             tbl.Columns=LoadColumns(tbl);

             // Mark the primary key
             string PrimaryKey=GetPK(tbl.Name);
             var pkColumn=tbl.Columns.SingleOrDefault(x=>x.Name.ToLower().Trim()==PrimaryKey.ToLower().Trim());
             if(pkColumn!=null)
                 pkColumn.IsPK=true;
         }

         return result;
     }

     DbConnection _connection;
     DbProviderFactory _factory;

     List<Column> LoadColumns(Table tbl)
     {

         using (var cmd=_factory.CreateCommand())
         {
             cmd.Connection=_connection;
             cmd.CommandText=COLUMN_SQL;

             var p = cmd.CreateParameter();
             p.ParameterName = "@tableName";
             p.Value=tbl.Name;
             cmd.Parameters.Add(p);

             var result=new List<Column>();
             using (IDataReader rdr=cmd.ExecuteReader())
             {
                 while(rdr.Read())
                 {
                     Column col=new Column();
                     col.Name=rdr["ColumnName"].ToString();
                     col.PropertyName=CleanUp(col.Name);
                     col.PropertyType=GetPropertyType(rdr["DataType"].ToString());
                     col.IsNullable=rdr["IsNullable"].ToString()=="YES";
                     col.IsAutoIncrement=rdr["AUTOINC_INCREMENT"]!=DBNull.Value;
                     result.Add(col);
                 }
             }

             return result;
         }
     }

     string GetPK(string table){

         string sql=@"SELECT KCU.COLUMN_NAME
             FROM INFORMATION_SCHEMA.KEY_COLUMN_USAGE KCU
             JOIN INFORMATION_SCHEMA.TABLE_CONSTRAINTS TC
             ON KCU.CONSTRAINT_NAME=TC.CONSTRAINT_NAME
             WHERE TC.CONSTRAINT_TYPE='PRIMARY KEY'
             AND KCU.TABLE_NAME=@tableName";

         using (var cmd=_factory.CreateCommand())
         {
             cmd.Connection=_connection;
             cmd.CommandText=sql;

             var p = cmd.CreateParameter();
             p.ParameterName = "@tableName";
             p.Value=table;
             cmd.Parameters.Add(p);

             var result=cmd.ExecuteScalar();

             if(result!=null)
                 return result.ToString();
         }             

         return "";
     }

     string GetPropertyType(string sqlType)
     {
         string sysType="string";
         switch (sqlType)
         {
             case "bigint":
                 sysType = "long";
                 break;
             case "smallint":
                 sysType= "short";
                 break;
             case "int":
                 sysType= "int";
                 break;
             case "uniqueidentifier":
                 sysType=  "Guid";
                  break;
             case "smalldatetime":
             case "datetime":
             case "date":
             case "time":
                 sysType=  "DateTime";
                   break;
             case "float":
                 sysType="double";
                 break;
             case "real":
                 sysType="float";
                 break;
             case "numeric":
             case "smallmoney":
             case "decimal":
             case "money":
                 sysType=  "decimal";
                  break;
             case "tinyint":
                 sysType = "byte";
                 break;
             case "bit":
                 sysType=  "bool";
                    break;
             case "image":
             case "binary":
             case "varbinary":
             case "timestamp":
                 sysType=  "byte[]";
                  break;
         }
         return sysType;
     }

     const string TABLE_SQL=@"SELECT *
         FROM  INFORMATION_SCHEMA.TABLES
         WHERE TABLE_TYPE='TABLE'";

     const string COLUMN_SQL=@"SELECT
             TABLE_CATALOG AS [Database],
             TABLE_SCHEMA AS Owner,
             TABLE_NAME AS TableName,
             COLUMN_NAME AS ColumnName,
             ORDINAL_POSITION AS OrdinalPosition,
             COLUMN_DEFAULT AS DefaultSetting,
             IS_NULLABLE AS IsNullable, DATA_TYPE AS DataType,
             AUTOINC_INCREMENT,
             CHARACTER_MAXIMUM_LENGTH AS MaxLength,
             DATETIME_PRECISION AS DatePrecision
         FROM  INFORMATION_SCHEMA.COLUMNS
         WHERE TABLE_NAME=@tableName
         ORDER BY OrdinalPosition ASC";

 }

 class PostGreSqlSchemaReader : SchemaReader
 {
     // SchemaReader.ReadSchema
     public override Tables ReadSchema(DbConnection connection, DbProviderFactory factory)
     {
         var result=new Tables();

         _connection=connection;
         _factory=factory;

         var cmd=_factory.CreateCommand();
         cmd.Connection=connection;
         cmd.CommandText=TABLE_SQL;

         //pull the tables in a reader
         using(cmd)
         {
             using (var rdr=cmd.ExecuteReader())
             {
                 while(rdr.Read())
                 {
                     Table tbl=new Table();
                     tbl.Name=rdr["table_name"].ToString();
                     tbl.Schema=rdr["table_schema"].ToString();
                     tbl.IsView=string.Compare(rdr["table_type"].ToString(), "View", true)==;
                     tbl.CleanName=CleanUp(tbl.Name);
                     tbl.ClassName=Inflector.MakeSingular(tbl.CleanName);
                     result.Add(tbl);
                 }
             }
         }

         foreach (var tbl in result)
         {
             tbl.Columns=LoadColumns(tbl);

             // Mark the primary key
             string PrimaryKey=GetPK(tbl.Name);
             var pkColumn=tbl.Columns.SingleOrDefault(x=>x.Name.ToLower().Trim()==PrimaryKey.ToLower().Trim());
             if(pkColumn!=null)
                 pkColumn.IsPK=true;
         }

         return result;
     }

     DbConnection _connection;
     DbProviderFactory _factory;

     List<Column> LoadColumns(Table tbl)
     {

         using (var cmd=_factory.CreateCommand())
         {
             cmd.Connection=_connection;
             cmd.CommandText=COLUMN_SQL;

             var p = cmd.CreateParameter();
             p.ParameterName = "@tableName";
             p.Value=tbl.Name;
             cmd.Parameters.Add(p);

             var result=new List<Column>();
             using (IDataReader rdr=cmd.ExecuteReader())
             {
                 while(rdr.Read())
                 {
                     Column col=new Column();
                     col.Name=rdr["column_name"].ToString();
                     col.PropertyName=CleanUp(col.Name);
                     col.PropertyType=GetPropertyType(rdr["udt_name"].ToString());
                     col.IsNullable=rdr["is_nullable"].ToString()=="YES";
                     col.IsAutoIncrement = rdr["column_default"].ToString().StartsWith("nextval(");
                     result.Add(col);
                 }
             }

             return result;
         }
     }

     string GetPK(string table){

         string sql=@"SELECT kcu.column_name
             FROM information_schema.key_column_usage kcu
             JOIN information_schema.table_constraints tc
             ON kcu.constraint_name=tc.constraint_name
             WHERE lower(tc.constraint_type)='primary key'
             AND kcu.table_name=@tablename";

         using (var cmd=_factory.CreateCommand())
         {
             cmd.Connection=_connection;
             cmd.CommandText=sql;

             var p = cmd.CreateParameter();
             p.ParameterName = "@tableName";
             p.Value=table;
             cmd.Parameters.Add(p);

             var result=cmd.ExecuteScalar();

             if(result!=null)
                 return result.ToString();
         }             

         return "";
     }

     string GetPropertyType(string sqlType)
     {
         switch (sqlType)
         {
             case "int8":
             case "serial8":
                 return "long";

             case "bool":
                 return "bool";

             case "bytea    ":
                 return "byte[]";

             case "float8":
                 return "double";

             case "int4":
             case "serial4":
                 return "int";

             case "money    ":
                 return "decimal";

             case "numeric":
                 return "decimal";

             case "float4":
                 return "float";

             case "int2":
                 return "short";

             case "time":
             case "timetz":
             case "timestamp":
             case "timestamptz":
             case "date":
                 return "DateTime";

             case "uuid":
                 return "Guid";

             default:
                 return "string";
         }
     }

     const string TABLE_SQL=@"
             SELECT table_name, table_schema, table_type
             FROM information_schema.tables
             WHERE (table_type='BASE TABLE' OR table_type='VIEW')
                 AND table_schema NOT IN ('pg_catalog', 'information_schema');
             ";

     const string COLUMN_SQL=@"
             SELECT column_name, is_nullable, udt_name, column_default
             FROM information_schema.columns
             WHERE table_name=@tableName;
             ";

 }

 class MySqlSchemaReader : SchemaReader
 {
     // SchemaReader.ReadSchema
     public override Tables ReadSchema(DbConnection connection, DbProviderFactory factory)
     {
         var result=new Tables();

         var cmd=factory.CreateCommand();
         cmd.Connection=connection;
         cmd.CommandText=TABLE_SQL;

         //pull the tables in a reader
         using(cmd)
         {
             using (var rdr=cmd.ExecuteReader())
             {
                 while(rdr.Read())
                 {
                     Table tbl=new Table();
                     tbl.Name=rdr["TABLE_NAME"].ToString();
                     tbl.Schema=rdr["TABLE_SCHEMA"].ToString();
                     tbl.IsView=string.Compare(rdr["TABLE_TYPE"].ToString(), "View", true)==;
                     tbl.CleanName=CleanUp(tbl.Name);
                     tbl.ClassName=Inflector.MakeSingular(tbl.CleanName);
                     result.Add(tbl);
                 }
             }
         }

         //this will return everything for the DB
         var schema  = connection.GetSchema("COLUMNS");

         //loop again - but this time pull by table name
         foreach (var item in result)
         {
             item.Columns=new List<Column>();

             //pull the columns from the schema
             var columns = schema.Select("TABLE_NAME='" + item.Name + "'");
             foreach (var row in columns)
             {
                 Column col=new Column();
                 col.Name=row["COLUMN_NAME"].ToString();
                 col.PropertyName=CleanUp(col.Name);
                 col.PropertyType=GetPropertyType(row);
                 col.IsNullable=row["IS_NULLABLE"].ToString()=="YES";
                 col.IsPK=row["COLUMN_KEY"].ToString()=="PRI";
                 col.IsAutoIncrement=row["extra"].ToString().ToLower().IndexOf("auto_increment")>=;

                 item.Columns.Add(col);
             }
         }

         return result;

     }

     static string GetPropertyType(DataRow row)
     {
         bool bUnsigned = row["COLUMN_TYPE"].ToString().IndexOf("unsigned")>=;
         string propType="string";
         switch (row["DATA_TYPE"].ToString())
         {
             case "bigint":
                 propType= bUnsigned ? "ulong" : "long";
                 break;
             case "int":
                 propType= bUnsigned ? "uint" : "int";
                 break;
             case "smallint":
                 propType= bUnsigned ? "ushort" : "short";
                 break;
             case "guid":
                 propType=  "Guid";
                  break;
             case "smalldatetime":
             case "date":
             case "datetime":
             case "timestamp":
                 propType=  "DateTime";
                   break;
             case "float":
                 propType="float";
                 break;
             case "double":
                 propType="double";
                 break;
             case "numeric":
             case "smallmoney":
             case "decimal":
             case "money":
                 propType=  "decimal";
                  break;
             case "bit":
             case "bool":
             case "boolean":
                 propType=  "bool";
                 break;
             case "tinyint":
                 propType =  bUnsigned ? "byte" : "sbyte";
                 break;
             case "image":
             case "binary":
             case "blob":
             case "mediumblob":
             case "longblob":
             case "varbinary":
                 propType=  "byte[]";
                  break;

         }
         return propType;
     }

     const string TABLE_SQL=@"
             SELECT *
             FROM information_schema.tables
             WHERE (table_type='BASE TABLE' OR table_type='VIEW') AND TABLE_SCHEMA=DATABASE()
             ";

 }

 class OracleSchemaReader : SchemaReader
 {
     // SchemaReader.ReadSchema
     public override Tables ReadSchema(DbConnection connection, DbProviderFactory factory)
     {
         var result=new Tables();

         _connection=connection;
         _factory=factory;

         var cmd=_factory.CreateCommand();
         cmd.Connection=connection;
         cmd.CommandText=TABLE_SQL;
         cmd.GetType().GetProperty("BindByName").SetValue(cmd, true, null);
         cmd.GetType().GetProperty("InitialLONGFetchSize").SetValue(cmd, -, null);

         //pull the tables in a reader
         using(cmd)
         {

             using (var rdr=cmd.ExecuteReader())
             {
                 while(rdr.Read())
                 {
                     Table tbl=new Table();
                     tbl.Name=rdr["TABLE_NAME"].ToString();
                     tbl.Schema = rdr["TABLE_SCHEMA"].ToString();
                     tbl.IsView=string.Compare(rdr["TABLE_TYPE"].ToString(), "View", true)==;
                     tbl.CleanName=CleanUp(tbl.Name);
                     tbl.ClassName=Inflector.MakeSingular(tbl.CleanName);
                     result.Add(tbl);
                 }
             }
         }

         foreach (var tbl in result)
         {
             tbl.Columns=LoadColumns(tbl);

             // Mark the primary key
             string PrimaryKey=GetPK(tbl.Name);
             var pkColumn=tbl.Columns.SingleOrDefault(x=>x.Name.ToLower().Trim()==PrimaryKey.ToLower().Trim());
             if(pkColumn!=null)
                 pkColumn.IsPK=true;
         }

         return result;
     }

     DbConnection _connection;
     DbProviderFactory _factory;

     List<Column> LoadColumns(Table tbl)
     {

         using (var cmd=_factory.CreateCommand())
         {
             cmd.Connection=_connection;
             cmd.CommandText=COLUMN_SQL;
             cmd.GetType().GetProperty("BindByName").SetValue(cmd, true, null);
             cmd.GetType().GetProperty("InitialLONGFetchSize").SetValue(cmd, -, null);

             var p = cmd.CreateParameter();
             p.ParameterName = ":tableName";
             p.Value=tbl.Name;
             cmd.Parameters.Add(p);

             var result=new List<Column>();
             using (IDataReader rdr=cmd.ExecuteReader())
             {
                 while(rdr.Read())
                 {
                     Column col=new Column();
                     col.Name=rdr["ColumnName"].ToString();
                     col.PropertyName=CleanUp(col.Name);
                     col.PropertyType=GetPropertyType(rdr["DataType"].ToString(), (rdr["DataScale"] == DBNull.Value ? null : rdr["DataScale"].ToString()));
                     col.IsNullable = "YES".Equals(rdr["isnullable"].ToString()) || "Y".Equals(rdr["isnullable"].ToString());
                     col.IsAutoIncrement=true;
                     result.Add(col);
                 }
             }

             return result;
         }
     }

     string GetPK(string table){

         string sql=@"select column_name from USER_CONSTRAINTS uc
   inner join USER_CONS_COLUMNS ucc on uc.constraint_name = ucc.constraint_name
 where uc.constraint_type = 'P'
 and uc.table_name = upper(:tableName)
 and ucc.position = 1";

         using (var cmd=_factory.CreateCommand())
         {
             cmd.Connection=_connection;
             cmd.CommandText=sql;
             cmd.GetType().GetProperty("BindByName").SetValue(cmd, true, null);
             cmd.GetType().GetProperty("InitialLONGFetchSize").SetValue(cmd, -, null);

             var p = cmd.CreateParameter();
             p.ParameterName = ":tableName";
             p.Value=table;
             cmd.Parameters.Add(p);

             var result=cmd.ExecuteScalar();

             if(result!=null)
                 return result.ToString();
         }             

         return "";
     }

     string GetPropertyType(string sqlType, string dataScale)
     {
         string sysType="string";
         sqlType = sqlType.ToLower();
         switch (sqlType)
         {
             case "bigint":
                 sysType = "long";
                 break;
             case "smallint":
                 sysType= "short";
                 break;
             case "int":
                 sysType= "int";
                 break;
             case "uniqueidentifier":
                 sysType=  "Guid";
                  break;
             case "smalldatetime":
             case "datetime":
             case "date":
                 sysType=  "DateTime";
                   break;
             case "float":
                 sysType="double";
                 break;
             case "real":
             case "numeric":
             case "smallmoney":
             case "decimal":
             case "money":
             case "number":
                 sysType=  "decimal";
                  break;
             case "tinyint":
                 sysType = "byte";
                 break;
             case "bit":
                 sysType=  "bool";
                    break;
             case "image":
             case "binary":
             case "varbinary":
             case "timestamp":
                 sysType=  "byte[]";
                  break;
         }

         if (sqlType == "number" && dataScale == "")
             return "long";

         return sysType;
     }

     const string TABLE_SQL=@"select TABLE_NAME, 'Table' TABLE_TYPE, USER TABLE_SCHEMA
 from USER_TABLES
 union all
 select VIEW_NAME, 'View', USER
 from USER_VIEWS";

     const string COLUMN_SQL=@"select table_name TableName,
  column_name ColumnName,
  data_type DataType,
  data_scale DataScale,
  nullable IsNullable
  from USER_TAB_COLS utc
  where table_name = :tableName
  and virtual_column = 'NO'
  order by column_id";

 }

 /// <summary>
 /// Summary for the Inflector class
 /// </summary>
 public static class Inflector {
     private static readonly List<InflectorRule> _plurals = new List<InflectorRule>();
     private static readonly List<InflectorRule> _singulars = new List<InflectorRule>();
     private static readonly List<string> _uncountables = new List<string>();

     /// <summary>
     /// Initializes the <see cref="Inflector"/> class.
     /// </summary>
     static Inflector() {
         AddPluralRule("$", "s");
         AddPluralRule("s$", "s");
         AddPluralRule("(ax|test)is$", "$1es");
         AddPluralRule("(octop|vir)us$", "$1i");
         AddPluralRule("(alias|status)$", "$1es");
         AddPluralRule("(bu)s$", "$1ses");
         AddPluralRule("(buffal|tomat)o$", "$1oes");
         AddPluralRule("([ti])um$", "$1a");
         AddPluralRule("sis$", "ses");
         AddPluralRule("(?:([^f])fe|([lr])f)$", "$1$2ves");
         AddPluralRule("(hive)$", "$1s");
         AddPluralRule("([^aeiouy]|qu)y$", "$1ies");
         AddPluralRule("(x|ch|ss|sh)$", "$1es");
         AddPluralRule("(matr|vert|ind)ix|ex$", "$1ices");
         AddPluralRule("([m|l])ouse$", "$1ice");
         AddPluralRule("^(ox)$", "$1en");
         AddPluralRule("(quiz)$", "$1zes");

         AddSingularRule("s$", String.Empty);
         AddSingularRule("ss$", "ss");
         AddSingularRule("(n)ews$", "$1ews");
         AddSingularRule("([ti])a$", "$1um");
         AddSingularRule("((a)naly|(b)a|(d)iagno|(p)arenthe|(p)rogno|(s)ynop|(t)he)ses$", "$1$2sis");
         AddSingularRule("(^analy)ses$", "$1sis");
         AddSingularRule("([^f])ves$", "$1fe");
         AddSingularRule("(hive)s$", "$1");
         AddSingularRule("(tive)s$", "$1");
         AddSingularRule("([lr])ves$", "$1f");
         AddSingularRule("([^aeiouy]|qu)ies$", "$1y");
         AddSingularRule("(s)eries$", "$1eries");
         AddSingularRule("(m)ovies$", "$1ovie");
         AddSingularRule("(x|ch|ss|sh)es$", "$1");
         AddSingularRule("([m|l])ice$", "$1ouse");
         AddSingularRule("(bus)es$", "$1");
         AddSingularRule("(o)es$", "$1");
         AddSingularRule("(shoe)s$", "$1");
         AddSingularRule("(cris|ax|test)es$", "$1is");
         AddSingularRule("(octop|vir)i$", "$1us");
         AddSingularRule("(alias|status)$", "$1");
         AddSingularRule("(alias|status)es$", "$1");
         AddSingularRule("^(ox)en", "$1");
         AddSingularRule("(vert|ind)ices$", "$1ex");
         AddSingularRule("(matr)ices$", "$1ix");
         AddSingularRule("(quiz)zes$", "$1");

         AddIrregularRule("person", "people");
         AddIrregularRule("man", "men");
         AddIrregularRule("child", "children");
         AddIrregularRule("sex", "sexes");
         AddIrregularRule("tax", "taxes");
         AddIrregularRule("move", "moves");

         AddUnknownCountRule("equipment");
         AddUnknownCountRule("information");
         AddUnknownCountRule("rice");
         AddUnknownCountRule("money");
         AddUnknownCountRule("species");
         AddUnknownCountRule("series");
         AddUnknownCountRule("fish");
         AddUnknownCountRule("sheep");
     }

     /// <summary>
     /// Adds the irregular rule.
     /// </summary>
     /// <param name="singular">The singular.</param>
     /// <param name="plural">The plural.</param>
     private static void AddIrregularRule(string singular, string plural) {
         AddPluralRule(String.Concat("(", singular[], ")", singular.Substring(), "$"), String.Concat("$1", plural.Substring()));
         AddSingularRule(String.Concat("(", plural[], ")", plural.Substring(), "$"), String.Concat("$1", singular.Substring()));
     }

     /// <summary>
     /// Adds the unknown count rule.
     /// </summary>
     /// <param name="word">The word.</param>
     private static void AddUnknownCountRule(string word) {
         _uncountables.Add(word.ToLower());
     }

     /// <summary>
     /// Adds the plural rule.
     /// </summary>
     /// <param name="rule">The rule.</param>
     /// <param name="replacement">The replacement.</param>
     private static void AddPluralRule(string rule, string replacement) {
         _plurals.Add(new InflectorRule(rule, replacement));
     }

     /// <summary>
     /// Adds the singular rule.
     /// </summary>
     /// <param name="rule">The rule.</param>
     /// <param name="replacement">The replacement.</param>
     private static void AddSingularRule(string rule, string replacement) {
         _singulars.Add(new InflectorRule(rule, replacement));
     }

     /// <summary>
     /// Makes the plural.
     /// </summary>
     /// <param name="word">The word.</param>
     /// <returns></returns>
     public static string MakePlural(string word) {
         return ApplyRules(_plurals, word);
     }

     /// <summary>
     /// Makes the singular.
     /// </summary>
     /// <param name="word">The word.</param>
     /// <returns></returns>
     public static string MakeSingular(string word) {
         return ApplyRules(_singulars, word);
     }

     /// <summary>
     /// Applies the rules.
     /// </summary>
     /// <param name="rules">The rules.</param>
     /// <param name="word">The word.</param>
     /// <returns></returns>
     private static string ApplyRules(IList<InflectorRule> rules, string word) {
         string result = word;
         if (!_uncountables.Contains(word.ToLower())) {
             for (int i = rules.Count - ; i >= ; i--) {
                 string currentPass = rules[i].Apply(word);
                 if (currentPass != null) {
                     result = currentPass;
                     break;
                 }
             }
         }
         return result;
     }

     /// <summary>
     /// Converts the string to title case.
     /// </summary>
     /// <param name="word">The word.</param>
     /// <returns></returns>
     public static string ToTitleCase(string word) {
         return Regex.Replace(ToHumanCase(AddUnderscores(word)), @"\b([a-z])",
             delegate(Match match) { return match.Captures[].Value.ToUpper(); });
     }

     /// <summary>
     /// Converts the string to human case.
     /// </summary>
     /// <param name="lowercaseAndUnderscoredWord">The lowercase and underscored word.</param>
     /// <returns></returns>
     public static string ToHumanCase(string lowercaseAndUnderscoredWord) {
         return MakeInitialCaps(Regex.Replace(lowercaseAndUnderscoredWord, @"_", " "));
     }

     /// <summary>
     /// Adds the underscores.
     /// </summary>
     /// <param name="pascalCasedWord">The pascal cased word.</param>
     /// <returns></returns>
     public static string AddUnderscores(string pascalCasedWord) {
         return Regex.Replace(Regex.Replace(Regex.Replace(pascalCasedWord, @"([A-Z]+)([A-Z][a-z])", "$1_$2"), @"([a-z\d])([A-Z])", "$1_$2"), @"[-\s]", "_").ToLower();
     }

     /// <summary>
     /// Makes the initial caps.
     /// </summary>
     /// <param name="word">The word.</param>
     /// <returns></returns>
     public static string MakeInitialCaps(string word) {
         return String.Concat(word.Substring(, ).ToUpper(), word.Substring().ToLower());
     }

     /// <summary>
     /// Makes the initial lower case.
     /// </summary>
     /// <param name="word">The word.</param>
     /// <returns></returns>
     public static string MakeInitialLowerCase(string word) {
         return String.Concat(word.Substring(, ).ToLower(), word.Substring());
     }

     /// <summary>
     /// Determine whether the passed string is numeric, by attempting to parse it to a double
     /// </summary>
     /// <param name="str">The string to evaluated for numeric conversion</param>
     /// <returns>
     ///     <c>true</c> if the string can be converted to a number; otherwise, <c>false</c>.
     /// </returns>
     public static bool IsStringNumeric(string str) {
         double result;
         return (double.TryParse(str, NumberStyles.Float, NumberFormatInfo.CurrentInfo, out result));
     }

     /// <summary>
     /// Adds the ordinal suffix.
     /// </summary>
     /// <param name="number">The number.</param>
     /// <returns></returns>
     public static string AddOrdinalSuffix(string number) {
         if (IsStringNumeric(number)) {
             int n = int.Parse(number);
             int nMod100 = n % ;

             if (nMod100 >=  && nMod100 <= )
                 return String.Concat(number, "th");

             switch (n % ) {
                 case :
                     return String.Concat(number, "st");
                 case :
                     return String.Concat(number, "nd");
                 case :
                     return String.Concat(number, "rd");
                 default:
                     return String.Concat(number, "th");
             }
         }
         return number;
     }

     /// <summary>
     /// Converts the underscores to dashes.
     /// </summary>
     /// <param name="underscoredWord">The underscored word.</param>
     /// <returns></returns>
     public static string ConvertUnderscoresToDashes(string underscoredWord) {
         return underscoredWord.Replace('_', '-');
     }

     #region Nested type: InflectorRule

     /// <summary>
     /// Summary for the InflectorRule class
     /// </summary>
     private class InflectorRule {
         /// <summary>
         ///
         /// </summary>
         public readonly Regex regex;

         /// <summary>
         ///
         /// </summary>
         public readonly string replacement;

         /// <summary>
         /// Initializes a new instance of the <see cref="InflectorRule"/> class.
         /// </summary>
         /// <param name="regexPattern">The regex pattern.</param>
         /// <param name="replacementText">The replacement text.</param>
         public InflectorRule(string regexPattern, string replacementText) {
             regex = new Regex(regexPattern, RegexOptions.IgnoreCase);
             replacement = replacementText;
         }

         /// <summary>
         /// Applies the specified word.
         /// </summary>
         /// <param name="word">The word.</param>
         /// <returns></returns>
         public string Apply(string word) {
             if (!regex.IsMatch(word))
                 return null;

             string replace = regex.Replace(word, replacement);
             if (word == word.ToUpper())
                 replace = replace.ToUpper();

             return replace;
         }
     }

     #endregion
 }

 #>

PetaPoco.Core.ttinclude

至此已经从数据库获取到了注释，下面需要将注释插入到T4模板中

修改PetaPoco.Generator.ttinclude

141行原始：

...
<# if (GeneratePocos) { #>
<#
foreach(Table tbl in from t in tables where !t.Ignore select t)
{
#>

<# if (string.IsNullOrEmpty(tbl.Schema)) { #>
    [TableName("<#=tbl.Name#>")]
...

添加表的Description注释：

...
<# if (GeneratePocos) { #>
<#
foreach(Table tbl in from t in tables where !t.Ignore select t)
{
#>
    /// <summary>
    /// <#=tbl.Description??""#>
    /// </summary>

<# if (string.IsNullOrEmpty(tbl.Schema)) { #>
    [TableName("<#=tbl.Name#>")]
...

167行原始：

...
    public partial class <#=tbl.ClassName#> <# if (GenerateOperations) { #>: <#=RepoName#>.Record<<#=tbl.ClassName#>> <# } #>
    {
<#
foreach(Column col in from c in tbl.Columns where !c.Ignore select c)
{
        // Column bindings
#>
<# if (TrackModifiedColumns) { #>
...

添加列的Description注释：

...
    public partial class <#=tbl.ClassName#> <# if (GenerateOperations) { #>: <#=RepoName#>.Record<<#=tbl.ClassName#>> <# } #>
    {
<#
foreach(Column col in from c in tbl.Columns where !c.Ignore select c)
{
        // Column bindings
#>
    /// <summary>
    /// <#=col.Description??""#>
    /// </summary>

<# if (TrackModifiedColumns) { #>
...

这样就改完了，打开database.tt按ctrl+s就能更新获取到的注释了

另外GetInstance居然不是单例方法，这简直没法忍，果断改掉：

PetaPoco.Generator.ttinclude，38行修改为：

...
        public static <#=RepoName#> GetInstance()
        {
            if (_instance!=null)
                return _instance;

            if (Factory!=null)
                return Factory.GetInstance();
            //else
            //    return new <#=RepoName#>();
            return _instance = new <#=RepoName#>();
        }
...