PetaPoco更新记录方法

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <param name="tableName">The name of the table to update</param>
         /// <param name="primaryKeyName">The name of the primary key column of the table</param>
         /// <param name="poco">The POCO object that specifies the column values to be updated</param>
         /// <param name="primaryKeyValue">The primary key of the record to be updated</param>
         /// <returns>The number of affected records</returns>
         public int Update(string tableName, string primaryKeyName, object poco, object primaryKeyValue)
         {
             if (string.IsNullOrEmpty(tableName))
                 throw new ArgumentNullException("tableName");

             if (string.IsNullOrEmpty(primaryKeyName))
                 throw new ArgumentNullException("primaryKeyName");

             if (poco == null)
                 throw new ArgumentNullException("poco");

             return ExecuteUpdate(tableName, primaryKeyName, poco, primaryKeyValue, null);
         }

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <param name="tableName">The name of the table to update</param>
         /// <param name="primaryKeyName">The name of the primary key column of the table</param>
         /// <param name="poco">The POCO object that specifies the column values to be updated</param>
         /// <param name="primaryKeyValue">The primary key of the record to be updated</param>
         /// <param name="columns">The column names of the columns to be updated, or null for all</param>
         /// <returns>The number of affected rows</returns>
         public int Update(string tableName, string primaryKeyName, object poco, object primaryKeyValue, IEnumerable<string> columns)
         {
             if (string.IsNullOrEmpty(tableName))
                 throw new ArgumentNullException("tableName");

             if (string.IsNullOrEmpty(primaryKeyName))
                 throw new ArgumentNullException("primaryKeyName");

             if (poco == null)
                 throw new ArgumentNullException("poco");

             return ExecuteUpdate(tableName, primaryKeyName, poco, primaryKeyValue, columns);
         }

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <param name="tableName">The name of the table to update</param>
         /// <param name="primaryKeyName">The name of the primary key column of the table</param>
         /// <param name="poco">The POCO object that specifies the column values to be updated</param>
         /// <returns>The number of affected rows</returns>
         public int Update(string tableName, string primaryKeyName, object poco)
         {
             return Update(tableName, primaryKeyName, poco, null);
         }

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <param name="tableName">The name of the table to update</param>
         /// <param name="primaryKeyName">The name of the primary key column of the table</param>
         /// <param name="poco">The POCO object that specifies the column values to be updated</param>
         /// <param name="columns">The column names of the columns to be updated, or null for all</param>
         /// <returns>The number of affected rows</returns>
         public int Update(string tableName, string primaryKeyName, object poco, IEnumerable<string> columns)
         {
             if (string.IsNullOrEmpty(tableName))
                 throw new ArgumentNullException("tableName");

             if (string.IsNullOrEmpty(primaryKeyName))
                 throw new ArgumentNullException("primaryKeyName");

             if (poco == null)
                 throw new ArgumentNullException("poco");

             return ExecuteUpdate(tableName, primaryKeyName, poco, null, columns);
         }

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <param name="poco">The POCO object that specifies the column values to be updated</param>
         /// <param name="columns">The column names of the columns to be updated, or null for all</param>
         /// <returns>The number of affected rows</returns>
         public int Update(object poco, IEnumerable<string> columns)
         {
             return Update(poco, null, columns);
         }

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <param name="poco">The POCO object that specifies the column values to be updated</param>
         /// <returns>The number of affected rows</returns>
         public int Update(object poco)
         {
             return Update(poco, null, null);
         }

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <param name="poco">The POCO object that specifies the column values to be updated</param>
         /// <param name="primaryKeyValue">The primary key of the record to be updated</param>
         /// <returns>The number of affected rows</returns>
         public int Update(object poco, object primaryKeyValue)
         {
             return Update(poco, primaryKeyValue, null);
         }

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <param name="poco">The POCO object that specifies the column values to be updated</param>
         /// <param name="primaryKeyValue">The primary key of the record to be updated</param>
         /// <param name="columns">The column names of the columns to be updated, or null for all</param>
         /// <returns>The number of affected rows</returns>
         public int Update(object poco, object primaryKeyValue, IEnumerable<string> columns)
         {
             if (poco == null)
                 throw new ArgumentNullException("poco");

             var pd = PocoData.ForType(poco.GetType(), _defaultMapper);
             return ExecuteUpdate(pd.TableInfo.TableName, pd.TableInfo.PrimaryKey, poco, primaryKeyValue, columns);
         }

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <typeparam name="T">The POCO class who's attributes specify the name of the table to update</typeparam>
         /// <param name="sql">The SQL update and condition clause (ie: everything after "UPDATE tablename"</param>
         /// <param name="args">Arguments to any embedded parameters in the SQL</param>
         /// <returns>The number of affected rows</returns>
         public int Update<T>(string sql, params object[] args)
         {
             if (string.IsNullOrEmpty(sql))
                 throw new ArgumentNullException("sql");

             var pd = PocoData.ForType(typeof(T), _defaultMapper);
             return Execute(string.Format("UPDATE {0} {1}", _provider.EscapeTableName(pd.TableInfo.TableName), sql), args);
         }

         /// <summary>
         ///     Performs an SQL update
         /// </summary>
         /// <typeparam name="T">The POCO class who's attributes specify the name of the table to update</typeparam>
         /// <param name="sql">
         ///     An SQL builder object representing the SQL update and condition clause (ie: everything after "UPDATE
         ///     tablename"
         /// </param>
         /// <returns>The number of affected rows</returns>
         public int Update<T>(Sql sql)
         {
             if (sql == null)
                 throw new ArgumentNullException("sql");

             var pd = PocoData.ForType(typeof(T), _defaultMapper);
             return Execute(new Sql(string.Format("UPDATE {0}", _provider.EscapeTableName(pd.TableInfo.TableName))).Append(sql));
         }

         private int ExecuteUpdate(string tableName, string primaryKeyName, object poco, object primaryKeyValue, IEnumerable<string> columns)
         {
             try
             {
                 OpenSharedConnection();
                 try
                 {
                     using (var cmd = CreateCommand(_sharedConnection, ""))
                     {
                         var sb = new StringBuilder();
                         var index = ;
                         var pd = PocoData.ForObject(poco, primaryKeyName, _defaultMapper);
                         if (columns == null)
                         {
                             foreach (var i in pd.Columns)
                             {
                                 // Don't update the primary key, but grab the value if we don't have it
                                 if (string.Compare(i.Key, primaryKeyName, true) == )
                                 {
                                     if (primaryKeyValue == null)
                                         primaryKeyValue = i.Value.GetValue(poco);
                                     continue;
                                 }

                                 // Dont update result only columns
                                 if (i.Value.ResultColumn)
                                     continue;

                                 // Build the sql
                                 if (index > )
                                     sb.Append(", ");
                                 sb.AppendFormat("{0} = {1}{2}", _provider.EscapeSqlIdentifier(i.Key), _paramPrefix, index++);

                                 // Store the parameter in the command
                                 AddParam(cmd, i.Value.GetValue(poco), i.Value.PropertyInfo);
                             }
                         }
                         else
                         {
                             foreach (var colname in columns)
                             {
                                 var pc = pd.Columns[colname];

                                 // Build the sql
                                 if (index > )
                                     sb.Append(", ");
                                 sb.AppendFormat("{0} = {1}{2}", _provider.EscapeSqlIdentifier(colname), _paramPrefix, index++);

                                 // Store the parameter in the command
                                 AddParam(cmd, pc.GetValue(poco), pc.PropertyInfo);
                             }

                             // Grab primary key value
                             if (primaryKeyValue == null)
                             {
                                 var pc = pd.Columns[primaryKeyName];
                                 primaryKeyValue = pc.GetValue(poco);
                             }
                         }

                         // Find the property info for the primary key
                         PropertyInfo pkpi = null;
                         if (primaryKeyName != null)
                         {
                             PocoColumn col;
                             pkpi = pd.Columns.TryGetValue(primaryKeyName, out col)
                                 ? col.PropertyInfo
                                 : new { Id = primaryKeyValue }.GetType().GetProperties()[];
                         }

                         cmd.CommandText = string.Format("UPDATE {0} SET {1} WHERE {2} = {3}{4}",
                             _provider.EscapeTableName(tableName), sb.ToString(), _provider.EscapeSqlIdentifier(primaryKeyName), _paramPrefix, index++);
                         AddParam(cmd, primaryKeyValue, pkpi);

                         DoPreExecute(cmd);

                         // Do it
                         var retv = cmd.ExecuteNonQuery();
                         OnExecutedCommand(cmd);
                         return retv;
                     }
                 }
                 finally
                 {
                     CloseSharedConnection();
                 }
             }
             catch (Exception x)
             {
                 if (OnException(x))
                     throw;
                 return -;
             }
         }