PHP之Mysql常用SQL语句示例的深入分析 |
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本文标签：Mysql,SQL语句 1.插入数据 insert into表名(列名1,列名2,列名..) values(值1,值2,值...); insert into product(name, price, pic_path) values(Nike,500,uploads/3245.jpg);
2.更新数据 update 表名set列名1=值1,列名2=值2[where条件]; update product set name=LiNing, price=50where id=2;
3.删除数据 deletefrom表名[where条件]; deletefrom product where id=2;
4.查询所有数据 select*from表名;select*from product; 5.查询部份列 select列名1,列名2,列名N from表名; select name, price from product;
6.条件查询 # 比较 =, <, >, <=, >=, != select*from表名where列名=值;
select*from product where id=2;
# and 与
select*from表名where条件1and条件2and条件N;
select*from product where name=Nikeand price=50;
# or 或
select*from表名where条件1or条件2or条件N;
select*from product where name=Nikeor price>50;
# not 非
select*from表名wherenot条件1;
select*from product wherenot name=Nike;
#in 枚举
select*from表名where列名in(值1,值2,值N);
select*from product where id in(2,3,4,10);
select*from product where id notin(2,3,4,10);
#like 模糊查询
select*from表名where列名 like %值%;
select*from product where name like %Li%;
#between...and... 范围查询
select*from表名where列名 between 值and值;
select*from order where created between 2010-01-01and2011-01-01;
7.查询排序 select*from表名 order by列名排序方式; #排序方式: asc(升序，默认)，desc(降序)
select*from product order by created desc;
8.限制查询结果数量 select*from表名 limit 开始记录数,结果数量;select*from product limit 5; select*from product limit 2,5;
9.聚合函数 # count 总记录数 select count(列名)from student;
select count(id)from student;
# sum 总共
select sum(列名)from student;
select sum(age)from student;
# avg 平均值
select avg(列名)from student;
select avg(age)as avg_age from student;
# max 最大值
select max(列名)from student;
select max(age)from student;
# min 最小值
select min(列名)from student;
select min(age)from student;
10.子查询 select name from student where age<(select avg(age)from student ); select*from product where id in(select id from order );
11.连接查询 select s.username as stu_name, t.name as te_name from student s, teacher t where s.teacher_id=t.id; |
