一些sql用法例子【Updating】

create table ab(product_id int,product_name varchar(10), product_type_id varchar(10));

insert into ab values(1,'产品A','1,2'),(2,'产品B','2,3');

create table ac(product_type_id int,product_type_name varchar(10));

insert into ac values(1,'类别1'),(2,'类别2'),(3,'类别3');

select product_id,product_name,ab.product_type_id,group_concat(product_type_name) as typename from ab,ac where instr(ab.product_type_id,ac.product_type_id) group by product_id,product_name;

root @localhost : bbb 14:45:24>select * from ab;

+------------+--------------+-----------------+

| product_id | product_name | product_type_id |

+------------+--------------+-----------------+

|          1 | 产品A        | 1,2             |

|          2 | 产品B        | 2,3             |

+------------+--------------+-----------------+

2 rows in set (0.01 sec)

root @localhost : bbb 14:55:54>select * from ac;

+-----------------+-------------------+

| product_type_id | product_type_name |

+-----------------+-------------------+

|               1 | 类别1             |

|               2 | 类别2             |

|               3 | 类别3             |

+-----------------+-------------------+

3 rows in set (0.00 sec)
root @localhost : bbb 14:55:56>select product_id,product_name,ab.product_type_id,group_concat(product_type_name) as typename from ab,ac where instr(ab.product_type_id,ac.product_type_id) group by product_id,product_name;

+------------+--------------+-----------------+-----------------+

| product_id | product_name | product_type_id | typename        |

+------------+--------------+-----------------+-----------------+

|          1 | 产品A        | 1,2             | 类别2,类别1     |

|          2 | 产品B        | 2,3             | 类别2,类别3     |

+------------+--------------+-----------------+-----------------+

2 rows in set (0.01 sec)

root @localhost : bbb 14:56:00>

 select name from a where find_in_set (id ,(select ids from b where fid = 1))

CREATE TABLE `t` (
`id` int(11) DEFAULT NULL,
`id2` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=gbk
insert into t valeu(11,11),(12,12),(13,13);

root@test 03:44:32>select id,sum(id2),avg(id2) from t group by id with rollup;
+——+———-+———-+
| id | sum(id2) | avg(id2) |
+——+———-+———-+
| 11 | 11 | 11.0000 |
| 12 | 12 | 12.0000 |
| 13 | 13 | 13.0000 |
| NULL | 36 | 12.0000 |
+——+———-+———-+
4 rows in set (0.00 sec)

mysql> select * from table1;
+----+------+
| id | num  |
+----+------+
|  1 | 1001 |
|  2 | 1001 |
|  3 | 1001 |
|  4 | 1001 |
|  5 | 1002 |
|  6 | 1002 |
|  7 | 1001 |
|  8 | 1001 |
|  9 | 1002 |
+----+------+
9 rows in set (0.00 sec)

mysql> select num,
    ->  concat('连续',count(*) ,'次 从', min(sid) ,'至',eid) as cnt
    -> from (
    ->  select a.id as sid,max(b.id) as eid,a.num
    ->  from table1 a , table1 b
    ->  where a.id<=b.id
    ->  and a.num=b.num
    ->  and not exists (select 1 from table1 where id between a.id and b.id and num!=a.num)
    ->  group by a.id
    -> ) t
    -> group by eid;
+------+----------------+
| num  | cnt            |
+------+----------------+
| 1001 | 连续4次 从1至4 |
| 1002 | 连续2次 从5至6 |
| 1001 | 连续2次 从7至8 |
| 1002 | 连续1次 从9至9 |
+------+----------------+
4 rows in set (0.00 sec)

mysql>

SELECT max(`date`),maxId,minId FROM (SELECT `date`,IF(fromId>toId,fromId,toId) AS maxId,IF(fromId>toId,toId,fromId) AS minId FROM `table`) AS `tmp` GROUP BY maxId,minId

select name,
sum(CASE WHEN class ='数学' THEN score END) as `数学`,
sum(CASE WHEN class ='语文' THEN score END) as `语文`,
from table_1 
where name='张三'
group by name

select id,(select count(*) from tab where pid=t.id) as 子结点数
from tab t
where pid=0

update xyz inner join (select max(if(状态='已完成',0,1)) as K from abc group by 工程ID) b on xyz.工程ID=b.工程ID
set 全部完成=IF(b.K=0,'是','否')

CREATE TABLE `goods` (
  `id` mediumint(8) unsigned NOT NULL AUTO_INCREMENT,
  `brand_id` varchar(5)  NOT NULL DEFAULT '0',
  `name` varchar(10) NOT NULL,
  `click_count` varchar(10)  NOT NULL DEFAULT '0',
  `number` varchar(5)  NOT NULL DEFAULT '0',
  `salesnum` varchar(10) NOT NULL DEFAULT '0',
  `desc` varchar(10) NOT NULL,
  PRIMARY KEY (`id`)

) ENGINE=InnoDB CHARACTER SET utf8;


INSERT INTO `goods` VALUES (901,  '26', 'T恤---售馨', '939', '1', '', '');
INSERT INTO `goods` VALUES (783,  '26', '雪纺上衣', '639', '5', '', '');
INSERT INTO `goods` VALUES (814,  '26', '雪纺上衣', '1059', '19', '', '');
INSERT INTO `goods` VALUES (1577, '26', '短袖荷叶领', '647', '87', '', '');
INSERT INTO `goods` VALUES (1769, '26', '透气纯色纽扣上衣', '2451', '24', '', '');
INSERT INTO `goods` VALUES (1642, '26', ' 纯色短袖', '534', '64', '', '');

-- 注意 find_in_set 中的待匹配字符串不允许有空格
mysql> SELECT * FROM `goods` WHERE id IN ('783','769','814','1577','1769') ORDER BY FIND_IN_SET(id, '783,769,814,1577,1769' ) ;
+------+----------+--------------------------+-------------+--------+----------+------+
| id   | brand_id | name                     | click_count | number | salesnum | desc |
+------+----------+--------------------------+-------------+--------+----------+------+
|  783 | 26       | 雪纺上衣                 | 639         | 5      |          |      |
|  814 | 26       | 雪纺上衣                 | 1059        | 19     |          |      |
| 1577 | 26       | 短袖荷叶领               | 647         | 87     |          |      |
| 1769 | 26       | 透气纯色纽扣上衣         | 2451        | 24     |          |      |
+------+----------+--------------------------+-------------+--------+----------+------+
4 rows in set (0.02 sec)

mysql> SELECT * FROM `goods` WHERE id IN ('783','769','814','1577','1769') ORDER BY FIND_IN_SET(id, '814,1577,1769,783,769' ) ;
+------+----------+--------------------------+-------------+--------+----------+------+
| id   | brand_id | name                     | click_count | number | salesnum | desc |
+------+----------+--------------------------+-------------+--------+----------+------+
|  814 | 26       | 雪纺上衣                 | 1059        | 19     |          |      |
| 1577 | 26       | 短袖荷叶领               | 647         | 87     |          |      |
| 1769 | 26       | 透气纯色纽扣上衣         | 2451        | 24     |          |      |
|  783 | 26       | 雪纺上衣                 | 639         | 5      |          |      |
+------+----------+--------------------------+-------------+--------+----------+------+
4 rows in set (0.00 sec)

mysql>

create table t1(
id int,
key1 int,
key2 int,
key3 int,
key4 int
);
insert into t1 values
(1, 112, 222, 333, null),
(2, 112, 222, 333, null),
(3, 134, 222, 333, 444 ),
(4, 134, 000, 333, 444 ),
(5, 178, 212, 312, 412 );

create table t2(
id int
);
insert into t2 values
(1),
(1),
(2),
(4),
(5);

SELECT  a.`key1`,a.`key2`,a.`key3`,a.`key4`,COUNT(DISTINCT b.id) FROM t1 a
LEFT JOIN t2 b ON a.`id`=b.`id`
GROUP BY a.`key1`,a.`key2`,a.`key3`,a.`key4`;

create table tt(
id  int,
`key` int,
type varchar(10)
);
insert into tt values
(123,11111,	  "first"),
(456,11111,	 "second"),
(456,11111,     "second" ),
(789,22222,     "second" ),
(890,22222,     "second" ),
(456,22222,      "first" );

select `key`,count(*),sum(if(type='first',1,0)),
sum(if(type='second',1,0))
from (
select distinct id,`key`,type from tt) a
group by `key`;

DELIMITER $$
DROP PROCEDURE IF EXISTS tt$$
CREATE PROCEDURE tt()
BEGIN
SET @i=1;
SET @a=CONCAT(CURDATE(),' 00:00:00');
insert into lsb values(date_add(@a, interval 10 minute));
 WHILE @i<=144 DO
insert into lsb values(date_add(@a, interval 10 minute));
 
 SET @a=DATE_ADD(@a, INTERVAL 10 MINUTE);
 SET @i=@i+1;
 END WHILE;
 END$$
DELIMITER ;

select TIMESTAMPDIFF(day,recdate,'2013-08-26') div 5,sum(weight)
from tb 
group by  TIMESTAMPDIFF(day,recdate,'2013-08-26') div 5

select table1.id,group_concat(table2.value1)
from table1,table2
where find_in_set(table2.id,table1.table2_id)
group by table1.id

select A.*
from tb A,tb B
where A.name=B.name and A.testorder = B.testorder-1 and A.score>B.score;

或者：

select * from TABLE A
where exists (select 1 from TABLE where A.score> score and A.name = name and testorder = 2)
and A.testorder = 1;

CREATE TABLE user_test(
  id int,
  uid int
);

insert into user_test values(11,22),(22, 33),(44, 22),(11,22),(22, 33),(44, 22);

update user_test
set 
    id = case when id in (44) then 4444 else id end,
    uid = case when uid in(22) then 2222 else uid end
where id > 0;

select A.* from (
select stdno, score from score where subjectId = 3 order by score desc) B
inner join score A
on A.stdno = B.stdno order by B.score desc, A.subjectId asc;

select *
from score s
order by (select score from score where stdno=s.stdno and subject=3) desc, a.subject asc;

CREATE TABLE `test` (
  `id`int(11) NOT NULL  auto_increment,
  `cnt` double(15,3) NOT NULL,
  PRIMARY KEY (`id`)
)ENGINE=InnoDB AUTO_INCREMENT=167 DEFAULT CHARSET=utf8 PACK_KEYS=0;

分2条SQL执行，
UPDATE、INSERT
或者：
INSERT INTO  test4(id,cnt) VALUES
 (167,2),
 (4,3),
 (6,5),
 (7,9)
ON DUPLICATE KEY UPDATE id = VALUES(id), cnt= VALUES(cnt)+  cnt

108.聚合去重查询优化：count(1) 在列为 Null 时的陷阱：
	--谈谈分布式Aggregation
	Q1：SELECT A, COUNT(DISTINCT B), SUM(C) FROM T GROUP BY A;
	Q2：SELECT A, COUNT(1), SUM(SC) FROM 
       (SELECT A, COUNT(1), SUM(C) AS SC 
       FROM T GROUP BY A, B) TT GROUP BY A;
	Q1和Q2的语义在B有null的时候并不等价，将Q2改为如下，这样两个查询的语义就是相同的了：
	SELECT A, COUNT(B), SUM(SC) FROM (SELECT A, B, SUM(C) AS SC FROM T GROUP BY A, B) TT GROUP BY A
109.查询一段时间内的用户下单次数分布情况：
	-- 首先计算每个用户的下单次数，然后使用 CASE..WHEN 语法来分组。
	SELECT 
		CASE
			WHEN c < 10 THEN '<10'
			WHEN c < 20 THEN '<20'
			WHEN c < 100 THEN '<100'
			ELSE '>100'
		END,
		COUNT(*)
	FROM (
		SELECT user_id, COUNT(*) AS c FROM events
		WHERE date BETWEEN '2015-09-01' AND '2015-09-20' AND event = 'SubmitOrder'
		GROUP BY 1
	)a 
	GROUP BY 1
110.查询做了行为 A 而没有做行为 B 的用户数
	--使用 LEFT OUTER JOIN 计算差集。
	SELECT a.user_id FROM (
		SELECT DISTINCT user_id FROM events WHERE date='2015-10-1' AND event = 'BuyGold'
	) a
	LEFT OUTER JOIN (
		SELECT DISTINCT user_id FROM events WHERE date='2015-10-1' AND event = 'SaleGold'
	) b
	ON a.user_id = b.user_id
	WHERE b.user_id IS NULL
111.计算用户的使用时长
	--使用分析函数，根据每个用户相邻的两个事件的间隔估算累计使用时长，如果两次使用间隔超出10分钟则不计算。
	SELECT
	user_id,
	SUM(
		CASE WHEN
			end_time - begin_time < 600
		THEN
			end_time - begin_time
		ELSE
			0
		END
	) FROM (
		SELECT
			user_id,
			EXTRACT(EPOCH FROM time) AS end_time,
			LAG(EXTRACT(EPOCH FROM time), 1, NULL) OVER (PARTITION BY user_id ORDER BY time asc) AS begin_time
		FROM events
		WHERE date='2015-5-1'
	) a
	GROUP BY 1
112.查询漏斗第 1 步的流失用户的使用时长
	SELECT
	AVG(
		CASE WHEN
			end_time - begin_time < 600
		THEN
			end_time - begin_time
		ELSE
			0
		END
	) FROM (
		SELECT
			user_id,
			EXTRACT(EPOCH FROM time) AS end_time,
			LAG(EXTRACT(EPOCH FROM time), 1, NULL) OVER (PARTITION BY user_id ORDER BY time asc) AS begin_time
		FROM events
		WHERE date='2015-5-1' and user_id in (funnel_user(12, '2015-05-01', '2015-05-01', '1.8', true, 0))
	) a