精妙SQL语句介绍
1. 说明:复制表(只复制结构,源表名:a,新表名:b) SQL: select * into b from a where 1<>1; 2. 说明:拷贝表(拷贝数据,源表名:a,目标表名:b) SQL: insert into b(a, b, c) select d, e, f from b; 3. 说明:显示文章、提交人和最后回复时间 select a.title, a.username, b.adddate from table a,( select max(adddate) adddate from table where table.title=a.title) b 4. 说明:外连接查询(表名1:a,表名2:b) select a.a, a.b, a.c, b.c, b.d, b.f from a LEFT OUT JOIN b ON a.a = b.c;5. 说明:日程安排提前