sqlserver数据库里sql 语句查看表里的约束，要查出 约束名、列名、约束类型、触发器

主键约束
SELECT
  tab.name AS [表名],idx.name AS [主键名称],col.name AS [主键列名]
FROM
  sys.indexes idx
    JOIN sys.index_columns idxcol 
      ON (idx.object_id = idxcol.object_id 
          AND idx.index_id = idxcol.index_id 
          AND idx.is_primary_key = 1)
    JOIN sys.tables tab
      ON (idx.object_id = tab.object_id)
    JOIN sys.columns col
      ON (idx.object_id = col.object_id
          AND idxcol.column_id = col.column_id);

唯一约束
SELECT
  tab.name AS [表名],idx.name AS [约束名称],col.name AS [约束列名]
FROM
  sys.indexes idx
    JOIN sys.index_columns idxcol 
      ON (idx.object_id = idxcol.object_id 
          AND idx.index_id = idxcol.index_id 
          AND idx.is_unique_constraint = 1)
    JOIN sys.tables tab
      ON (idx.object_id = tab.object_id)
    JOIN sys.columns col
      ON (idx.object_id = col.object_id
          AND idxcol.column_id = col.column_id);

外键约束
select 
  oSub.name  AS  [子表名称],fk.name AS  [外键名称],SubCol.name AS [子表列名],oMain.name  AS  [主表名称],MainCol.name AS [主表列名]
from 
  sys.foreign_keys fk  
    JOIN sys.all_objects oSub  
        ON (fk.parent_object_id = oSub.object_id)
    JOIN sys.all_objects oMain 
        ON (fk.referenced_object_id = oMain.object_id)
    JOIN sys.foreign_key_columns fkCols 
        ON (fk.object_id = fkCols.constraint_object_id)
    JOIN sys.columns SubCol 
        ON (oSub.object_id = SubCol.object_id  
            AND fkCols.parent_column_id = SubCol.column_id)
    JOIN sys.columns MainCol 
        ON (oMain.object_id = MainCol.object_id  
            AND fkCols.referenced_column_id = MainCol.column_id)

Check约束
SELECT
  tab.name AS [表名],chk.name AS [Check约束名],col.name AS [列名],chk.deFinition
FROM
  sys.check_constraints chk
    JOIN sys.tables tab
      ON (chk.parent_object_id = tab.object_id)
    JOIN sys.columns col
      ON (chk.parent_object_id = col.object_id
          AND chk.parent_column_id = col.column_id)

 获取表名及表的触发器

select 
 (select b.name from sysobjects as b where b.id = a.parent_obj)  表名,   a.name  as 触发器 
   from sysobjects  as a where a.xtype='TR'
order by 表名

备注：

xtype   char(2)   对象类型。可以是下列对象类型中的一种：     
  C   =   CHECK   约束   
  D   =   默认值或   DEFAULT   约束   
  F   =   FOREIGN   KEY   约束   
  L   =   日志   
  FN   =   标量函数   
  IF   =   内嵌表函数   
  P   =   存储过程   
  PK   =   PRIMARY   KEY   约束（类型是   K）   
  RF   =   复制筛选存储过程   
  S   =   系统表   
  TF   =   表函数   
  TR   =   触发器   
  U   =   用户表   
  UQ   =   UNIQUE   约束（类型是   K）   
  V   =   视图   
  X   =   扩展存储过程