Mysql常用SQL语句收集
基础篇
- //查询时间,友好提示
- $sql = "select date_format(create_time, '%Y-%m-%d') as day from table_name";
- //int 时间戳类型
- $sql = "select from_unixtime(create_time, '%Y-%m-%d') as day from table_name";
- //一个sql返回多个总数
- $sql = "select count(*) all, " ;
- $sql .= " count(case when status = 1 then status end) status_1_num, ";
- $sql .= " count(case when status = 2 then status end) status_2_num ";
- $sql .= " from table_name";
- //Update Join / Delete Join
- $sql = "update table_name_1 ";
- $sql .= " inner join table_name_2 on table_name_1.id = table_name_2.uid ";
- $sql .= " inner join table_name_3 on table_name_3.id = table_name_1.tid ";
- $sql .= " set *** = *** ";
- $sql .= " where *** ";
- //delete join 同上。
- //替换某字段的内容的语句
- $sql = "update table_name set content = REPLACE(content, 'aaa', 'bbb') ";
- $sql .= " where (content like '%aaa%')";
- //获取表中某字段包含某字符串的数据
- $sql = "SELECT * FROM `表名` WHERE LOCATE('关键字', 字段名) ";
- //获取字段中的前4位
- $sql = "SELECT SUBSTRING(字段名,1,4) FROM 表名 ";
- //查找表中多余的重复记录
- //单个字段
- $sql = "select * from 表名 where 字段名 in ";
- $sql .= "(select 字段名 from 表名 group by 字段名 having count(字段名) > 1 )";
- //多个字段
- $sql = "select * from 表名 别名 where (别名.字段1,别名.字段2) in ";
- $sql .= "(select 字段1,字段2 from 表名 group by 字段1,字段2 having count(*) > 1 )";
- //删除表中多余的重复记录(留id最小)
- //单个字段
- $sql = "delete from 表名 where 字段名 in ";
- $sql .= "(select 字段名 from 表名 group by 字段名 having count(字段名) > 1) ";
- $sql .= "and 主键ID not in ";
- $sql .= "(select min(主键ID) from 表名 group by 字段名 having count(字段名 )>1) ";
- //多个字段
- $sql = "delete from 表名 别名 where (别名.字段1,别名.字段2) in ";
- $sql .= "(select 字段1,字段2 from 表名 group by 字段1,字段2 having count(*) > 1) ";
- $sql .= "and 主键ID not in ";
- $sql .= "(select min(主键ID) from 表名 group by 字段1,字段2 having count(*)>1) ";
业务篇
连续范围问题
- //创建测试表
- CREATE TABLE `test_number` (
- `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
- `number` int(11) unsigned NOT NULL DEFAULT '0' COMMENT '数字',
- PRIMARY KEY (`id`)
- ) ENGINE=innodb DEFAULT CHARSET=utf8
- //创建测试数据
- insert into test_number values(1,1);
- insert into test_number values(2,2);
- insert into test_number values(3,3);
- insert into test_number values(4,5);
- insert into test_number values(5,7);
- insert into test_number values(6,8);
- insert into test_number values(7,10);
- insert into test_number values(8,11);
实验目标:求数字的连续范围。
根据上面的数据,应该得到的范围。
- 1-3
- 5-5
- 7-8
- 10-11
- //执行Sql
- select min(number) start_range,max(number) end_range
- from
- (
- select number,rn,number-rn diff from
- (
- select number,@number:=@number+1 rn from test_number,(select @number:=0) as number
- ) b
- ) c group by diff;
数字的连续范围
签到问题
- //创建参考表(模拟数据需要用到)
- CREATE TABLE `test_nums` (
- `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
- PRIMARY KEY (`id`)
- ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='参考表';
- //模拟数据,插入 1-10000 连续数据.
- //创建测试表
- CREATE TABLE `test_sign_history` (
- `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
- `uid` int(11) unsigned NOT NULL DEFAULT '0' COMMENT '用户ID',
- `create_time` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP COMMENT '签到时间',
- PRIMARY KEY (`id`)
- ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='签到历史表';
- //创建测试数据
- insert into test_sign_history(uid,create_time)
- select ceil(rand()*10000),str_to_date('2016-12-11','%Y-%m-%d')+interval ceil(rand()*10000) minute
- from test_nums where id<31;
- //统计每天的每小时用户签到情况
- select
- h,
- sum(case when create_time='2016-12-11' then c else 0 end) 11Sign,
- sum(case when create_time='2016-12-12' then c else 0 end) 12Sign,
- sum(case when create_time='2016-12-13' then c else 0 end) 13Sign,
- sum(case when create_time='2016-12-14' then c else 0 end) 14Sign,
- sum(case when create_time='2016-12-15' then c else 0 end) 15Sign,
- sum(case when create_time='2016-12-16' then c else 0 end) 16Sign,
- sum(case when create_time='2016-12-17' then c else 0 end) 17Sign
- from
- (
- select
- date_format(create_time,'%Y-%m-%d') create_time,
- hour(create_time) h,
- count(*) c
- from test_sign_history
- group by
- date_format(create_time,'%Y-%m-%d'),
- hour(create_time)
- ) a
- group by h with rollup;
统计每天的每小时用户签到情况
- //统计每天的每小时用户签到情况(当某个小时没有数据时,显示0)
- select
- h ,
- sum(case when create_time='2016-12-11' then c else 0 end) 11Sign,
- sum(case when create_time='2016-12-12' then c else 0 end) 12Sign,
- sum(case when create_time='2016-12-13' then c else 0 end) 13Sign,
- sum(case when create_time='2016-12-14' then c else 0 end) 14Sign,
- sum(case when create_time='2016-12-15' then c else 0 end) 15Sign,
- sum(case when create_time='2016-12-16' then c else 0 end) 16Sign,
- sum(case when create_time='2016-12-17' then c else 0 end) 17Sign
- from
- (
- select b.h h,c.create_time,c.c from
- (
- select id-1 h from test_nums where id<=24
- ) b
- left join
- (
- select
- date_format(create_time,'%Y-%m-%d') create_time,
- hour(create_time) h,
- count(*) c
- from test_sign_history
- group by
- date_format(create_time,'%Y-%m-%d'),
- hour(create_time)
- ) c on (b.h=c.h)
- ) a
- group by h with rollup;
统计每天的每小时用户签到情况(当某个小时没有数据时,显示0)
- //统计每天的用户签到数据和每天的增量数据
- select
- type,
- sum(case when create_time='2016-12-11' then c else 0 end) 11Sign,
- sum(case when create_time='2016-12-12' then c else 0 end) 12Sign,
- sum(case when create_time='2016-12-13' then c else 0 end) 13Sign,
- sum(case when create_time='2016-12-14' then c else 0 end) 14Sign,
- sum(case when create_time='2016-12-15' then c else 0 end) 15Sign,
- sum(case when create_time='2016-12-16' then c else 0 end) 16Sign,
- sum(case when create_time='2016-12-17' then c else 0 end) 17Sign
- from
- (
- select b.create_time,ifnull(b.c-c.c,0) c,'Increment' type from
- (
- select
- date_format(create_time,'%Y-%m-%d') create_time,
- count(*) c
- from test_sign_history
- group by
- date_format(create_time,'%Y-%m-%d')
- ) b
- left join
- (
- select
- date_format(create_time,'%Y-%m-%d') create_time,
- count(*) c
- from test_sign_history
- group by
- date_format(create_time,'%Y-%m-%d')
- ) c on(b.create_time=c.create_time+ interval 1 day)
- union all
- select
- date_format(create_time,'%Y-%m-%d') create_time,
- count(*) c,
- 'Current'
- from test_sign_history
- group by
- date_format(create_time,'%Y-%m-%d')
- ) a
- group by type
- order by case when type='Current' then 1 else 0 end desc;
统计每天的用户签到数据和每天的增量数据
- //模拟不同的用户签到了不同的天数
- insert into test_sign_history(uid,create_time)
- select uid,create_time + interval ceil(rand()*10) day from test_sign_history,test_nums
- where test_nums.id <10 order by rand() limit 150;
- //统计签到天数相同的用户数量
- select
- sum(case when day=1 then cn else 0 end) 1Day,
- sum(case when day=2 then cn else 0 end) 2Day,
- sum(case when day=3 then cn else 0 end) 3Day,
- sum(case when day=4 then cn else 0 end) 4Day,
- sum(case when day=5 then cn else 0 end) 5Day,
- sum(case when day=6 then cn else 0 end) 6Day,
- sum(case when day=7 then cn else 0 end) 7Day,
- sum(case when day=8 then cn else 0 end) 8Day,
- sum(case when day=9 then cn else 0 end) 9Day,
- sum(case when day=10 then cn else 0 end) 10Day
- from
- (
- select c day,count(*) cn
- from
- (
- select uid,count(*) c from test_sign_history group by uid
- ) a
- group by c
- ) b;
统计签到天数相同的用户数量
- //统计每个用户的连续签到时间
- select * from (
- select d.*,
- @ggid := @cggid,
- @cggid := d.uid,
- if(@ggid = @cggid, @grank := @grank + 1, @grank := 1) grank
- from
- (
- select uid,min(c.create_time) begin_date ,max(c.create_time) end_date,count(*) count from
- (
- select
- b.*,
- @gid := @cgid,
- @cgid := b.uid,
- if(@gid = @cgid, @rank := @rank + 1, @rank := 1) rank,
- b.diff-@rank flag from (
- select
- distinct
- uid,
- date_format(create_time,'%Y-%m-%d') create_time,
- datediff(create_time,now()) diff
- from test_sign_history order by uid,create_time
- ) b, (SELECT @gid := 1, @cgid := 1, @rank := 1) as a
- ) c group by uid,flag
- order by uid,count(*) desc
- ) d,(SELECT @ggid := 1, @cggid := 1, @grank := 1) as e
- )f
- where grank=1;