2_表中内容的增删改查

注意：

删除库和表用drop DB_abc; drop T_score;

删除表中行的内容用delete 列的内容drop column

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创建一张表：create table score(id int,name char(10),age int);

建完表后，可以查看表结构：desc score;

对表中的内容进行增、删、改、查操作：

1.增

insert into score

(id,name,age)

values

(3,"sanba",35);

insert into score

(id,name,age)

values

(1,"zhangsan",32),

(4,"zhouqi",22),

(5,"zhaoliu",33);

上面的是增加行，现在来增加列：alter table score add sex int;

2.删

delete from score

where id=1;

上面是删除行，现在来删除列：alter table score drop sex;

3.改

update score

set

id = 1

where

name="lisi";

4.查

select * from score;//查询表中所有的内容

select id,age from score;//查询表中id,age项

select id,age from score where id>2;//查询表中id,age项，并且id>2