SQL查看CHECK约束信息

        以下两个语句均基于系统表sysobjects、syscomments和系统视图sysconstraints，查询结果中包括表ID、表名、列ID、列名、CHECK约束ID、CHECK约束名、CHECK约束status值以及CHECK约束的内容，TCCView为Table-Column-Check View，结果中均为列级CHECK约束，TCView为Table-Check View，结果中均为表级CHECK约束。

       1.SELECT TOP 100 PERCENT a.id AS tableid, a.tablename, a.colid, a.columnname,
      a.datatype, a.length, b.constid AS checkid, b.checkname, b.status, b.content
FROM (SELECT sysobjects.name AS tablename, sysobjects.id,
              syscolumns.name AS columnname, syscolumns.colid,
              systypes.name AS datatype, syscolumns.length AS length
        FROM sysobjects, syscolumns, systypes
        WHERE sysobjects.xtype = 'u' AND sysobjects.id = syscolumns.id AND
              syscolumns.xtype = systypes.xtype AND
              systypes.xtype = systypes.xusertype AND sysobjects.status > 0)
      a LEFT OUTER JOIN
          (SELECT sysobjects.name checkname, sysobjects.status, sysconstraints.constid,
               sysconstraints.id, sysconstraints.colid, syscomments.text AS content
         FROM sysobjects, sysconstraints, syscomments
         WHERE xtype = 'c' AND sysobjects.id = sysconstraints.constid AND
               sysconstraints.constid = syscomments.id) b ON a.id = b.id AND
      a.colid = b.colid
ORDER BY a.tablename, a.columnname, b.checkname
   

     2.SELECT a.id AS tableid, a.tablename, b.constid AS checkid, b.checkname, b.status,
      b.content
FROM (SELECT sysobjects.id, sysobjects.name AS tablename
        FROM sysobjects
        WHERE sysobjects.xtype = 'u' AND sysobjects.status > 0) a LEFT OUTER JOIN
          (SELECT sysobjects.name checkname, sysobjects.status, sysconstraints.constid,
               sysconstraints.id, sysconstraints.colid, syscomments.text AS content
         FROM sysobjects, sysconstraints, syscomments
         WHERE xtype = 'c' AND sysobjects.id = sysconstraints.constid AND
               sysconstraints.constid = syscomments.id AND sysconstraints.colid = 0) b ON
      a.id = b.id