摘要： 1 Little Miss Mary Nobody seemed to care about Mary. She was born in India, where her father was a British official. He was busy with his work, and he 阅读全文

摘要： 1、SQL JOIN 语法（内连接） 内连接举例（下面的两个sql语句是完全相同的） select * from x,y where x.a = y.a select * from x join y on x.a = y.a 2、引入 ANSI SQL92，是为了 解决 外连接。 3、体会与下面语句 阅读全文