主键约束
SELECTtab.name AS [表名],idx.name AS [主键名称],col.name AS [主键列名]
FROMsys.indexes idxJOIN 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 tabON (idx.object_id = tab.object_id)JOIN sys.columns colON (idx.object_id = col.object_idAND idxCol.column_id = col.column_id);唯一约束
SELECTtab.name AS [表名],idx.name AS [约束名称],col.name AS [约束列名]
FROMsys.indexes idxJOIN 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 tabON (idx.object_id = tab.object_id)JOIN sys.columns colON (idx.object_id = col.object_idAND 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
SELECTtab.name AS [表名],chk.name AS [Check约束名],col.name AS [列名],chk.definition
FROMsys.check_constraints chkJOIN sys.tables tabON (chk.parent_object_id = tab.object_id)JOIN sys.columns colON (chk.parent_object_id = col.object_idAND chk.parent_column_id = col.column_id)