摘要:
1、exists的返回结果是bool型,只有true或者false 如 SELECT * FROM alumni_info t WHERE EXISTS(SELECT a_id FROM alumni_education e WHERE e.a_id='6588' ),返回的结果跟SELECT * 阅读全文
摘要:
select into select语句和select into from语句 1.INSERT INTO SELECT语句 语句形式为:Insert into Table2(field1,field2,...) select value1,value2,... from Table1 要求目标表T 阅读全文