sql语句转为Model

在跟数据库打交道的时候，有一个常用的应用，就是把数据库中的表转为程序中的对象，也就是说表中的列转为对象的属性。对于字段比较少的，我们可以直接复制过去改，但是字段数比较多的时候，借助工具类实现比较方便而且不易出错，看下我的代码：

         /// <summary>
         /// 从数据库sql语句中生成实体model
         /// </summary>
         /// <param name="sql"></param>
         /// <returns></returns>
         public static string GenerateModelFromSql(string sql)
         {
             StringBuilder modelBuild = new StringBuilder();

             string tableNamePatten = @"CREATE\s+TABLE\s+(?:\[dbo\]\.)?\[(\w+)\]";

             var m = Regex.Match(sql, tableNamePatten);
             var gs = m.Groups;
             var tableName = "";
             if (gs.Count > )
             {
                 tableName = gs[].Value;
                 modelBuild.AppendLine("///<summary>");
                 modelBuild.AppendLine(string.Format(" ///{0}", tableName));
                 modelBuild.AppendLine("///</summary>");

                 modelBuild.AppendLine(string.Format("public class {0}", tableName));

                 modelBuild.AppendLine("{");
             }

             string fieldPatten = @"\s*\[(\w+)\]\s+\[(\w+)\]\s*(\((\d+)\))?";
             string primarykeyPattern = @"primary\s+key";
             var matches = Regex.Matches(sql, fieldPatten);

             string fieldName = "";
             string fieldType = "";
             string stringLength = "";

             int i = ;
             foreach (Match item in matches)
             {
                 i++;
                 var groups = item.Groups;

                 if (groups.Count > )
                 {
                     fieldName = groups[].Value;
                     fieldType = groups[].Value;

                     if (groups.Count > )
                     {
                         stringLength = groups[].Value;
                     }

                     var type = Tools.ConvertToCSharpType(fieldType);

                     if (Regex.IsMatch(sql, primarykeyPattern) && i == )
                     {
                         modelBuild.AppendLine(" [PrimaryKey]");
                     }
                     else if (type == "string")
                     {
                         modelBuild.AppendLine(string.Format("   [StringLength({0})]", stringLength));
                     }

                     string core = string.Format("   public {0} {1} [set; get;]", type, fieldName);

                     core = core.Replace('[', '{');
                     core = core.Replace(']', '}');
                     modelBuild.AppendLine(core);
                 }
             }
             modelBuild.AppendLine("}");
             return modelBuild.ToString();
         }

使用最多的是正则匹配。再看第51行的类型转换：

         public static string ConvertToCSharpType(string fieldType)
         {
             string dataType = null;
             var t = fieldType.ToLower();
             if (t == "varchar" || t == "nvarchar")
             {
                 dataType = "string";
             }
             else if (t == "bit")
             {
                 dataType = "bool";
             }
             else if (t == "bigint")
             {
                 dataType = "long";
             }
             else if (t == "datetime")
             {
                 dataType = "DateTime";
             }
             else if (t == "byte" || t == "binary" || t == "varbinary" || t == "image")
             {
                 dataType = "byte[]";
             }
             else if (t == "uniqueidentifier")
             {
                 dataType = "Guid";
             }
             return dataType ?? t;
         }