判断字段是否存在：if not exists(select * from syscolumns where id=object_id('temphlxf') and name='czy') beginalter table temphlxf add czy varchar(50) not nullendGO判断主键是否存在：IF EXISTS (select * from sysobjects where parent_obj=object_id(N'temphlxf') and name='pk_temphlxf' and xtype='PK')BEGINALTER TABLE temphlxf drop Constraint pk_temphlxfENDGO判断某个字段是否具有not null约束：if exists (select * from syscolumns where id = OBJECT_ID('temphlxf') and name = 'czy' and isnullable=1)beginalter table temphlxf alter column czy varchar(50) not nullend GO
如果觉得《判断字段是否存在 判断主键是否存在 判断某个字段是否具有not null约束》对你有帮助，请点赞、收藏，并留下你的观点哦！
