员工表employee
| 建表语句： create table employee ( id int, name varchar(20), sex varchar(10), birthday date, salary float, resume text );数据： insert into employee values(1,"zhangsan","male","1980-11-25",2000,"good body"); insert into employee values(2,"lisi","male","1980-04-25",1000,"good body"); insert into employee values(3,"xiaohong","female","1978-11-25",4000,"good girl"); |
更新表数据
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1)将所有员工薪水修改为5000元
UPDATE employee SET salary =5000
2)将 员工薪水小于3000 的 在原有基础上 加 4000
UPDATE employee SET salary =salary+4000 WHERE salary <=3000
2)将姓名为’zhangsan’的员工薪水修改为3000元。
UPDATE employee SET salary = 3000 WHERE `NAME` ='zhangsan'
3)将姓名为’lisi’的员工薪水修改为4000元,sex改为female。
UPDATE employee SET salary = 4000 , sex = 'female' WHERE `NAME` ='lisi'
4)将xiaohong的薪水在原有基础上增加1000元。
UPDATE employee SET salary =salary+ 1000 WHERE `NAME` = 'zhangsan'
删除表数据
1) 删除表中所有数据 (最好不要轻易使用)
DELETE FROM 表名；
2) 带条件的删除
# zhangsan员工离职了 ，将 姓名为 'zhangsan' 的员工 删除掉
DELETE FROM employee WHERE `name` ='zhangsan'
# 延伸 truncate (最好不要轻易使用)
截断表，删除表中所有数据，并且自增长的列重新计数，效率比DELETE高。
格式 ： TRUNCATE 表名;
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ToBeContinue
