zoukankan      html  css  js  c++  java
  • 627. Swap Salary

    Given a table salary, such as the one below, that has m=male and f=female values. Swap all f and m values (i.e., change all f values to m and vice versa) with a single update query and no intermediate temp table.

    For example:

    | id | name | sex | salary |
    |----|------|-----|--------|
    | 1  | A    | m   | 2500   |
    | 2  | B    | f   | 1500   |
    | 3  | C    | m   | 5500   |
    | 4  | D    | f   | 500    |
    

    After running your query, the above salary table should have the following rows:

    | id | name | sex | salary |
    |----|------|-----|--------|
    | 1  | A    | f   | 2500   |
    | 2  | B    | m   | 1500   |
    | 3  | C    | f   | 5500   |
    | 4  | D    | m   | 500    |
    这是道mysql的题,意思是把表里面的男换成女,女换成男
    使用case即可
    可以说是很无聊了
    update salary set sex =(case sex when 'm' then 'f' else 'm' end);
  • 相关阅读:
    学习第23天
    学习第22天
    学习第21天
    Servlet交互与JSP
    Cookie与Session
    servlet入门
    网络编程
    DOM4j
    xml文档对象模型doc
    反射
  • 原文地址:https://www.cnblogs.com/icysnow/p/8136701.html
Copyright © 2011-2022 走看看