SqlServer字段说明查询（表基本信息查询）

--快速查看表结构（比较全面的）
SELECT  CASE WHEN col.colorder = 1 THEN obj.name
                  ELSE ''
             END AS 表名,
        col.colorder AS 序号 ,
        col.name AS 列名 ,
        ISNULL(ep.[value], '') AS 列说明 ,
        t.name AS 数据类型 ,
        col.length AS 长度 ,
        ISNULL(COLUMNPROPERTY(col.id, col.name, 'Scale'), 0) AS 小数位数 ,
        CASE WHEN COLUMNPROPERTY(col.id, col.name, 'IsIdentity') = 1 THEN '√'
             ELSE ''
        END AS 标识 ,
        CASE WHEN EXISTS ( SELECT   1
                           FROM     dbo.sysindexes si
                                    INNER JOIN dbo.sysindexkeys sik ON si.id = sik.id
                                                              AND si.indid = sik.indid
                                    INNER JOIN dbo.syscolumns sc ON sc.id = sik.id
                                                              AND sc.colid = sik.colid
                                    INNER JOIN dbo.sysobjects so ON so.name = si.name
                                                              AND so.xtype = 'PK'
                           WHERE    sc.id = col.id
                                    AND sc.colid = col.colid ) THEN '√'
             ELSE ''
        END AS 主键 ,
        CASE WHEN col.isnullable = 1 THEN '√'
             ELSE ''
        END AS 允许空 ,
        ISNULL(comm.text, '') AS 默认值
FROM    dbo.syscolumns col
        LEFT  JOIN dbo.systypes t ON col.xtype = t.xusertype
        inner JOIN dbo.sysobjects obj ON col.id = obj.id
                                         AND obj.xtype = 'U'
                                         AND obj.status >= 0
        LEFT  JOIN dbo.syscomments comm ON col.cdefault = comm.id
        LEFT  JOIN sys.extended_properties ep ON col.id = ep.major_id
                                                      AND col.colid = ep.minor_id
                                                      AND ep.name = 'MS_Description'
        LEFT  JOIN sys.extended_properties epTwo ON obj.id = epTwo.major_id
                                                         AND epTwo.minor_id = 0
                                                         AND epTwo.name = 'MS_Description'
WHERE   obj.name = 'Egression'--表名
ORDER BY col.colorder ;

上面代码适用于sqlserver数据库，只需要更改表名-->执行代码就可以获得表的基本信息（代码来自网络：http://blog.csdn.net/changhong009/article/details/29587063）

下面是简单代码（未测试）

SELECT t.[name] AS 表名,c.[name] AS 字段名,cast(ep.[value]
  as varchar(100)) AS [字段说明]
  FROM sys.tables AS t
  INNER JOIN sys.columns
  AS c ON t.object_id = c.object_id
   LEFT JOIN sys.extended_properties AS ep
  ON ep.major_id = c.object_id AND ep.minor_id = c.column_id WHERE ep.class =1
  AND t.name='TableName'