内连接是最常用的链接,也叫等值链接,最常见的格式是: SELECT a.*,b.* FROM TA as a ,TB as b WHERE a.id=b.id 外联接。外联接可以是左向外联接、右向外联接或完整外部联接。 LEFT JOIN 或 LEFT OUTER JOIN。 左向外联接的结果集包括 LEFT OUTER 子句中指定的左表的所有行,而不仅仅是联接列...【阅读全文】
mysql>grant ALL PRIVILEGES on *.* to user1@% identified by "password";mysql>grant ALL PRIVILEGES on *.* to "root"@"localhost" identified by "password";mysql>show grants for user1;mysql>drop user 'user1'@'%';mysql>revoke ALL PRIVILEGES from 'user1'@'%' identified by "password";flush privileges...【阅读全文】