增加一行中的列值

Question

我有以下存储过程从 MySql 中的当前日期获取过去 12 个月

DELIMITER $$
CREATE
PROCEDURE `Calendar`()
BEGIN
CREATE TEMPORARY TABLE IF NOT EXISTS `Cal` (
`month` INT(11) ,
`year` INT(11) 
);
TRUNCATE TABLE Cal;

SET @counter := -1;
WHILE (DATEDIFF(DATE(NOW()), DATE(DATE_SUB(NOW(),INTERVAL @counter MONTH))) < DATEDIFF(DATE(NOW()), DATE(DATE_SUB(NOW(),INTERVAL 12 MONTH)))) DO 
INSERT INTO Cal SELECT DATE_FORMAT(DATE_ADD(DATE_SUB(NOW(),INTERVAL 12 MONTH), INTERVAL @counter:=@counter + 1 MONTH),'%m'),DATE_FORMAT(DATE_ADD(DATE_SUB(NOW(),INTERVAL 12 MONTH), INTERVAL @counter + 1 MONTH),'%Y');
END WHILE;

SELECT * FROM `Cal`;
END$$
DELIMITER ;

DROP PROCEDURE IF EXISTS Calendar;

输出表是

9   2017
10  2017
11  2017
12  2018
1   2018
2   2018
3   2018
4   2018
5   2018
6   2018
7   2018
8   2018
9   2018

在第 12 个月，年份是 2018 年。应该是 2017 年，而且行 9 2017 不应该在那里，因为它是第 13 个月，包括当前月份。如何将第 12 个月的年份设为 2017 年并删除 9 2017 提前谢谢

Answer 1

这是一个存储过程，可以为您提供所需的输出。它比您尝试的更长但更简单。

DELIMITER //
DROP PROCEDURE IF EXISTS Calendar //
CREATE PROCEDURE Calendar ()
BEGIN
  DECLARE month INT DEFAULT MONTH(CURDATE());
  DECLARE year INT DEFAULT YEAR(CURDATE()) - 1;
  CREATE TEMPORARY TABLE CAL (month INT, year INT);
  REPEAT
    SET month = month + 1;
    IF (month = 13) THEN
      SET month = 1;
      SET year = year + 1;
    END IF;
    INSERT INTO CAL VALUES (month, year);
    UNTIL month = MONTH(CURDATE())
  END REPEAT;
  SELECT * FROM CAL;
  DROP TABLE CAL;
END //
DELIMITER ;
CALL Calendar();

输出：

 month  year    
 10     2017
 11     2017
 12     2017
  1     2018 
  2     2018
  3     2018
  4     2018
  5     2018
  6     2018
  7     2018
  8     2018
  9     2018

Answer 2

您也可以在不创建存储过程、临时表、插入临时表并在
之后删除存储过程的情况下执行此操作 通过在 MySQL 代码中使用数字生成器。

查询

SELECT 
   MONTH(NOW() - INTERVAL number_generator.number MONTH) AS `month`
 , YEAR(NOW() - INTERVAL number_generator.number MONTH) AS `year`
FROM (

 SELECT 
   (@NUMBER := @NUMBER + 1) AS number
 FROM (
    SELECT 1 AS number UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9 UNION SELECT 10
  ) AS records_1
  CROSS JOIN (
    SELECT 1 AS number UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9 UNION SELECT 10
  ) AS records_2
  CROSS JOIN (SELECT @NUMBER := 0) AS init_user_params  
) AS number_generator
WHERE
    number_generator.number BETWEEN 1 AND 12
  AND
    MONTH(NOW()) <> MONTH(NOW() - INTERVAL number_generator.number MONTH) 
ORDER BY 
    YEAR(NOW() - INTERVAL number_generator.number MONTH) ASC
  , MONTH(NOW() - INTERVAL number_generator.number MONTH) ASC

结果

| month | year |
|-------|------|
|    10 | 2017 |
|    11 | 2017 |
|    12 | 2017 |
|     1 | 2018 |
|     2 | 2018 |
|     3 | 2018 |
|     4 | 2018 |
|     5 | 2018 |
|     6 | 2018 |
|     7 | 2018 |
|     8 | 2018 |

查看演示http://sqlfiddle.com/#!9/340e01/584

请注意，如果您使用 MySQL 8.0+，则使用公用表表达式的语法会更清晰。

查询

WITH RECURSIVE number_generator (number) AS
(
  SELECT 1 AS number
  UNION ALL
  SELECT number + 1 FROM number_generator WHERE number < 12
)
SELECT 
   MONTH(NOW() - INTERVAL number_generator.number MONTH) AS `month`
 , YEAR(NOW() - INTERVAL number_generator.number MONTH) AS `year`
FROM 
 number_generator
WHERE
 MONTH(NOW()) <> MONTH(NOW() - INTERVAL number_generator.number MONTH) 
ORDER BY 
    YEAR(NOW() - INTERVAL number_generator.number MONTH) ASC
  , MONTH(NOW() - INTERVAL number_generator.number MONTH) ASC

结果

| month | year |
|-------|------|
|    10 | 2017 |
|    11 | 2017 |
|    12 | 2017 |
|     1 | 2018 |
|     2 | 2018 |
|     3 | 2018 |
|     4 | 2018 |
|     5 | 2018 |
|     6 | 2018 |
|     7 | 2018 |
|     8 | 2018 |

见演示https://www.db-fiddle.com/f/chJ4qS2ocXS79vGkFBg7PR/13