SQLServer database tables into the entity class annotated []

1. In the development process, and sometimes need to be converted to an entity class database table. Hand knocked out is not convenient, but also prone to error. In the DRY + lazy principle, reference is made to an old driver's blog blog [see bottom], and optimized on the basis thereof. [Originally] Without Comments

DECLARE @TableName sysname = 'TableName';
DECLARE @Result VARCHAR(MAX) = 'public class ' + @TableName + '
{';

SELECT  @Result = @Result  + CHAR(13) + '    ///<summary>' + CHAR(13)
        + '    ///' + CAST(desr AS NVARCHAR) + CHAR(13)
        + '    ///</summary>' + '
    public ' + ColumnType + NullableSign + ' ' + colname + ' '  + ' { get; set; }
    '
FROM    (SELECT    column_id ColumnId,
                    ISNULL(t.desctr, '') AS desr,
                    col.name colname,
                     CASE typ.name
                      WHEN 'bigint' THEN 'long'
                      WHEN 'binary' THEN 'byte[]'
                      WHEN 'bit' THEN 'bool'
                      WHEN 'char' THEN 'string'
                      WHEN 'date' THEN 'DateTime'
                      WHEN 'datetime' THEN 'DateTime'
                      WHEN 'datetime2' THEN 'DateTime'
                      WHEN 'datetimeoffset' THEN 'DateTimeOffset'
                      WHEN 'decimal' THEN 'decimal'
                      WHEN 'float' THEN 'float'
                      WHEN 'image' THEN 'byte[]'
                      WHEN 'int' THEN 'int'
                      WHEN 'money' THEN 'decimal'
                      WHEN 'nchar' THEN 'string'
                      WHEN 'ntext' THEN 'string'
                      WHEN 'numeric' THEN 'decimal'
                      WHEN 'nvarchar' THEN 'string'
                      WHEN 'real' THEN 'double'
                      WHEN 'smalldatetime' THEN 'DateTime'
                      WHEN 'smallint' THEN 'short'
                      WHEN 'smallmoney' THEN 'decimal'
                      WHEN 'text' THEN 'string'
                      WHEN 'time' THEN 'TimeSpan'
                      WHEN 'timestamp' THEN 'DateTime'
                      WHEN 'tinyint' THEN 'byte'
                      WHEN 'uniqueidentifier' THEN 'Guid'
                      WHEN 'varbinary' THEN 'byte[]'
                      WHEN 'varchar' THEN 'string'
                      ELSE 'UNKNOWN_' + typ.name
                    END ColumnType ,
                    CASE WHEN col.is_nullable = 1
                              AND typ.name IN ( 'bigint', 'bit', 'date',
                                                'datetime', 'datetime2',
                                                'datetimeoffset', 'decimal',
                                                'float', 'int', 'money',
                                                'numeric', 'real',
                                                'smalldatetime', 'smallint',
                                                'smallmoney', 'time',
                                                'tinyint', 'uniqueidentifier' )
                         THEN '?'
                         ELSE ''
                    END NullableSign
          FROM      sys.columns col
                   LEFT  JOIN ( SELECT  ISNULL(CAST(g.value AS VARCHAR), '') desctr ,
                                        g.minor_id AS minor_id
                                FROM    sys.extended_properties g
                                WHERE   g.major_id = OBJECT_ID(@TableName)
                              ) t ON t.minor_id = col.column_id
                    JOIN sys.types typ ON col.system_type_id = typ.system_type_id
                                          AND col.user_type_id = typ.user_type_id   
          WHERE     object_id = OBJECT_ID(@TableName)
        ) t
ORDER BY ColumnId;

SET @Result = @Result + '
}';

PRINT @Result;

Reference link: https: //www.cnblogs.com/bayes/p/6206297.html