create table student(
id char(36) primary key,
name varchar(8) not null,
age int(3) default 0,
mobile char(11),
address varchar(150)
)
insert into student
values ('9b4435ec-372c-456a-b287-e3c5aa23dff4','张三',24,'12345678901','北京海淀');
insert into student
values ('a273ea66-0a42-48d2-a17b-388a2feea244','李%四',10,'98765432130',null);
insert into student
values ('eb0a220a-60ae-47b6-9e6d-a901da9fe355','张李三',11,'18338945560','安徽六安');
insert into student
values ('6ab71673-9502-44ba-8db0-7f625f17a67d','王_五',28,'98765432130','北京朝阳区');
insert into student
values ('0055d61c-eb51-4696-b2da-506e81c3f566','王_五%%',11,'13856901237','吉林省长春市宽平区');
like:进行数据模糊查询
1、%:匹配0次或多次
select * from student where name like '张三%';
select * from student where name like '李%四';
2、_:只匹配1次
select * from student where name like '张_';
3、escape:取消%或_字符的通配符特性
注:escape后面单引号中只能是单个字符;
escape后面可以是字母、#、$、,、\等字符;
select * from student where name like '%A%%' escape 'A';
select * from student where name like '%A_%' escape 'A';
select * from student where name like '_A%_' escape 'A';
select * from student where name like '_A__' escape 'A';
4、逻辑条件:and、or
#查询张姓且地址中含有北京的学生信息
select * from student where name like '张%' and address like '%北京%';
#查询张姓或地址中含有北京的学生信息
select * from student where name like '张%' or address like '%北京%';
5、between 下限 and 上限:等同于“(column_name>=下限) and (column_name<=上限)”
注:“between 下限 and 上限”一定是小值在前大值在后,否则查不出数据;
“between 下限 and 上限”查询数据包括边界值;
#查询年龄在10~28之间的学生信息
select * from student where age between 10 and 28;
#上面SQL语句等效于该SQL语句
select * from student where age >= 10 and age<=28;
6、关系条件:=、!=、<、=<、>、>=等
select * from student where age<28;--查询年龄小于28岁的学生信息
7、in(value1,value2,value3…valuen):等同于“ column_name = value1 or column_name = value2 or column_name = value3… or column_name = valuen ”
select * from student where age in (11,24);
8、null :包括is null 和 is not null
select * from student where address is null;
select * from student where address is not null;