We look for additions and deletions to change search table of basic syntax:
First, create a simple salary scale:
create table salary(
id int primary key auto_increment,
sname varchar(10) not null default ' ',
gender char(1) not null default ' ',
company varchar(20) not null default ' ',
salary decimal(6,2) not null default 0.00,
fanbu smallint not null default 0
)engine myisam charset utf8;
Then we see the structure of the table: desc table name;
Next we add data to the table:
So where to tables to increase the line?
insert into 表名
But also where to columns that added value?
(id,sname,gender,company,salary,fanbu)
The increase in value is the number?
values
(1, ' John Doe ', ' M ', ' Baidu ', 8888.67,234)
The above code is knocked into a few that we look at the results:
Inserting a plurality of data words, separated by commas as long as the data can be:
If we insert the data at the time, if you do not declare a column, the default all columns.
改变表中的数据：update 表名 set 要修改的列=值 where 表达式;
例如：update salary set fanbu=100 where id=1;
注意我们在修改数据的时候一定要加上where 表达式，只要where表达式为真，那么该语句就执行，如果不加的话就会把这一列所有的值全部改掉。
删除：指的是删除整行，不存在删除一行中的某几列。
delete from 表名 where 条件;
上面的语句说的就是我们要删除哪张表中的哪几行。
比如我们要删除salary表中fanbu<150的行；
delete from salary where fanbu<150;
查询：要思考三个问题，查询哪张表，哪几列，哪几行？
我们来查找一下salary表中的姓名，性别和薪水：
select sname,gender,salary from salary;
上面的只实现了查询哪张表和哪几列，那么哪一行怎么实现呢？
答：添加where 表达式：
select sname,gender,salary from salary where sname='李四';
只要where表达式为真，那么该语句就执行，那么我们也可以换个条件，例如where salary=9534;等等