sql server 2008 删除表的 constraints
给定表名和列名删除列上的约束
抄来一段
DECLARE @tablename VARCHAR(100), @columnname VARCHAR(100), @tab VARCHAR(100) SET @tablename='CountryGroupEmailAndWaitAux' SET @columnname='actionOfHasNoValidEmail' declare @defname varchar(100) declare @cmd varchar(100) select @defname = name FROM sysobjects so JOIN sysconstraints sc ON so.id = sc.constid WHERE object_name(so.parent_obj) = @tablename AND so.xtype = 'D' AND sc.colid = (SELECT colid FROM syscolumns WHERE id = object_id(@tablename) AND name = @columnname) select @cmd='alter table '+ @tablename+ ' drop constraint '+ @defname if @cmd is null print 'No default constraint to drop' exec (@cmd)
由于实际应用里,需要改动表中大量字段的长度等属性,索性把约束都删掉重建了
改了下
给定表名直接删除所有的约束
USE [testdatabase]
DECLARE @tablename VARCHAR(100), @columnname VARCHAR(100), @coname VARCHAR(100) SET @tablename='testtable1' declare @cmd varchar(100) declare test_cursor cursor for select so.name as coname, sco.name as columnname FROM sysobjects so JOIN sysconstraints sc ON so.id = sc.constid inner join syscolumns sco on sc.colid = sco.colid WHERE object_name(so.parent_obj) = @tablename AND so.xtype = 'D' AND sco.id = OBJECT_ID(@tablename) open test_cursor fetch next from test_cursor into @coname , @columnname WHILE @@FETCH_STATUS = 0 BEGIN select @cmd='alter table '+ @tablename+ ' drop constraint '+ @coname if @cmd is null print 'No default constraint to drop' print @cmd --exec (@cmd) --去掉注释既可执行 FETCH NEXT FROM test_cursor into @coname , @columnname END CLOSE test_cursor DEALLOCATE test_cursor