• SQLServer之数据库表转化为实体类【带注释】


    1.在开发过程中,有时候需要将数据库表转化为实体类。手敲除了不方便,还容易出错。本着DRY+懒人原则,参考了一位老司机的博客【见底部】,并在其基础上进行了优化。【原先是不带注释的】

    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;

    最终效果如下:

    参考链接:https://www.cnblogs.com/bayes/p/6206297.html

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  • 原文地址:https://www.cnblogs.com/jerque/p/11388405.html
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