通过系统表sysobjects查询删除目标表的主键

declare @Pk nvarchar(100)
select @Pk = Name from sysobjects where Parent_Obj=OBJECT_ID('Hr_WorkPlan') and xtype='PK'----获取表主键字段名称
select @Pk
declare @SQL nvarchar(1000)
select @SQL = 'Alter table Hr_WorkPlan Drop '+@Pk
select @SQL
exec(@SQL)----执行存储过程
GO