1、最简单查询
select * from car;
2、查询指定列
select name,oil,powers from car;
3、对查出的列名修改名字
select name as ‘车名‘,oil as ‘油量‘,powers as ‘动力‘ from car;
4、按条件查询
select name,oil,powers from car where oil = 8.7;
5、多条件查询
select name oil,powers from car where oil = 8.7 or powers = 160;
select name oil,powers from car where oil = 8.7 and powers = 160;
6、范围查询
select * from car where price>=40 and price<=60;
select * from car where price between 40 and 60;
7、离散查询
select * from car where powers = 130 or powers = 150 or powers = 170;
select * from car where powers in(130,150,170);
select * from car where powers not in(130,150,170);
8、模糊查询
select * from car where name like ‘%宝马%‘; %号是所有字符
select * from car where name like ‘_宝马‘ ; _号是一个字符
9、排序查询 asc升序 desc降序 order对结果集进行排序
select * from car order by oil asc;
select * from car order by oil desc;
10、去重复查询 ?distinct
select distinct brand from car;
11、分页查询
select * from car limit 10,5; 第一个数字表示跳过的条数，第二个数字表示跳过后展示的条数。
n表示页数，m表示每页显示的条数
limit(n-1)*m,m;
12、聚合函数查询
count(列名) ????总数的意思
sum(列名) ??????求和的意思
avg(列名) ??????平均的意思
max(列名) min(列名)
select count(*) from car;
???select sum(price) from car;
???select avg(price) from car;
???select max(price) from car;
???select min(price) from car;
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增删改
1、添加表中数据
insert into car values(‘‘,‘‘,‘‘,‘‘);
insert into car(字段1，值1) values(字段2，值2）;
insert into car set 字符1，值1 vables(字符2，值2）;
2、修改表数据
update car set 字段1 = 值 where 字段2（要看字段类型） = 值2
3、删除表数据
delete from 表名 where 字段1 = 值1
PHP重点3---表中简单查询、增删改
原文地址：https://www.cnblogs.com/mjwwzy/p/9128649.html