摘要:
1 delete 语句嵌套子查询: 2 3 delete from 表名1 where 列名 操作符 (select 列名 from 表名2 where 条件); 4 5 示例: 6 delete from customers_1 where salary > (select avg(salary) from customers_1);[删除一个之后还会在重新计算av... 阅读全文
摘要:
1 1.逻辑运算符的补充 2 between 的用法:(在....之间) 3 select column1,column2,......columnN from 表名 4 where columnX between 第一个值 and 第二个值; 5 6 示例:select name,age from customers where age b... 阅读全文