查询是否有外键:
select object_name(a.parent_object_id) 'tables'
from sys.foreign_keys a
where a.referenced_object_id=object_id('[表名]')
更改主键类型:
---删除原主键
Alter table base_log Drop PK__BASE_LOG__4364C88276969D2E
---修改主键类型
ALTER table base_log ALTER COLUMN LOG_ID NVARCHAR(32)
---把所有主键设为不能为空
Alter table base_log alter column LOG_ID nvarChar(32) not null
---重建主键
Alter table base_log ADD CONSTRAINT PK__BASE_LOG__4364C88276969D2E PRIMARY KEY (LOG_ID)