关于SQL的内部表结构

SELECT DISTINCT
      TOP 100 PERCENT o.xtype,
      CASE o.xtype WHEN 'X' THEN '扩展存储过程'
                   WHEN 'TR' THEN '触发器'
                   WHEN 'PK' THEN '主键'
                   WHEN 'F' THEN '外键'
                   WHEN 'C' THEN '约束'
                   WHEN 'V' THEN '视图'
                   WHEN 'FN'THEN '函数-标量'
                   WHEN 'IF' THEN '函数-内嵌'
                   WHEN 'TF' THEN '函数-表值'
             ELSE '存储过程' END AS 类型,
       o.name AS 对象名, o.crdate AS 创建时间, o.refdate AS 更改时间,
      c.text AS 声明语句
FROM dbo.sysobjects o LEFT OUTER JOIN
      dbo.syscomments c ON o.id = c.id
WHERE (o.xtype IN ('X', 'TR', 'C', 'V', 'F', 'IF', 'TF', 'FN', 'P', 'PK')) AND
      (OBJECTPROPERTY(o.id, N'IsMSShipped') = 0)
ORDER BY CASE o.xtype WHEN 'X' THEN '扩展存储过程' WHEN 'TR' THEN '触发器' WHEN
       'PK' THEN '主键' WHEN 'F' THEN '外键' WHEN 'C'THEN '约束' WHEN 'V' THEN '视图'
       WHEN 'FN' THEN '函数-标量' WHEN 'IF' THEN '函数-内嵌' WHEN 'TF' THEN '函数-表值'
       ELSE '存储过程' END DESC
SELECT TOP 100 PERCENT --a.id,
      CASE WHEN a.colorder = 1 THEN d.name ELSE '' END AS 表名,
      CASE WHEN a.colorder = 1 THEN isnull(f.value,'') ELSE '' END AS 表说明,
      a.colorder AS 字段序号, a.name AS 字段名, CASE WHEN COLUMNPROPERTY(a.id,
      a.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 = a.id AND sc.colid = a.colid) THEN '√' ELSE '' END AS 主键,
      b.name AS 类型, a.length AS 长度, COLUMNPROPERTY(a.id, a.name, 'PRECISION')
      AS 精度, ISNULL(COLUMNPROPERTY(a.id, a.name, 'Scale'), 0) AS 小数位数,
      CASE WHEN a.isnullable = 1 THEN '√' ELSE '' END AS 允许空, ISNULL(e.text, '')
      AS 默认值, ISNULL(g.[value], '') AS 字段说明, d.crdate AS 创建时间,
      CASE WHEN a.colorder = 1 THEN d.refdate ELSE NULL END AS 更改时间
FROM dbo.syscolumns a LEFT OUTER JOIN
      dbo.systypes b ON a.xtype = b.xusertype INNER JOIN
      dbo.sysobjects d ON a.id = d.id AND d.xtype = 'U' AND
      d.status >= 0 LEFT OUTER JOIN
      dbo.syscomments e ON a.cdefault = e.id LEFT OUTER JOIN
dbo.sysproperties g ON a.id = g.id AND a.colid = g.smallid AND
      g.name = 'MS_Description' LEFT OUTER JOIN
      dbo.sysproperties f ON d.id = f.id AND f.smallid = 0 AND
      f.name = 'MS_Description'
ORDER BY d.name, a.colorder