数据表
create table tb_user ( id bigint auto_increment primary key, name varchar(16) not null, age int not null, address varchar(128) null ); insert into test.tb_user (id, name, age, address) values (1, '张三', 18, 'china'); insert into test.tb_user (id, name, age, address) values (2, '李四', 19, 'china'); insert into test.tb_user (id, name, age, address) values (3, 'jack', 20, 'america'); insert into test.tb_user (id, name, age, address) values (4, 'jane', 22, 'america'); insert into test.tb_user (id, name, age, address) values (5, 'pig', 19, 'japan'); insert into test.tb_user (id, name, age, address) values (6, 'cat', 22, 'japan');
一、使用field()函数自定义顺序
① 一个字段排序
优先china,其次america,最后japan
select name, address from tb_user order by field(address, 'china', 'america', 'japan') asc
asc可省略,如果有些数据不在指定范围内,则从最后开始按照默认排序
② 多个字段排序
先按照address升序排序,相同再按照name降序排序
select name, address from tb_user order by field(address, 'china', 'america', 'japan') asc, field(name, '李四', '张三', 'jane', 'jack') desc
二、使用case when自定义排序规则
① 一个字段
优先china,其次america,最后japan
select name, address from tb_user order by case address when 'china' then 1 when 'america' then 2 when 'japan' then 3 end, address asc
asc可省略
② 多个字段
先按照address排序,相同再按照name排序
select name, address from tb_user order by case address when 'china' then 1 when 'america' then 2 when 'japan' then 3 end, address asc, case name when '李四' then 1 when '张三' then 2 when 'jane' then 3 when 'jack' then 4 end, name desc
三、随机排序
使用rand()函数随机排序,不根据任何字段,每次的顺序都是随机的
select name, address from tb_user order by rand()
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