Mysql 常用 SQL 语句集锦

逃离我推掉我的手 2024-02-17 18:39 67阅读 0赞

摘要：Mysql 常用 SQL 语句集锦

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;

*  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(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;

//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;

原文地址： [https://gold.xitu.io/post/584e7b298d6d81005456eb53][https_gold.xitu.io_post_584e7b298d6d81005456eb53]

[https_gold.xitu.io_post_584e7b298d6d81005456eb53]: https://gold.xitu.io/post/584e7b298d6d81005456eb53