Question

我有一个break和clock_in_out表，我想从两者中获取所有值并将它们连接到user_id列。但是我在JOIN ON附近使用了不正确的synatx，而不是线索为什么..这是我的查询

SELECT * 
FROM `breaks` 
WHERE `user_id` = 1 
AND `in_date` LIKE '%2015-03-03%' 
AND `out_date` LIKE '%2015-03-03%' 
JOIN `clock_in_out` ON `breaks`.`user_id` = `clock_in_out`.`user_id` 
WHERE `loggedin_date` 
LIKE '%2015-03-03%' 
AND `loggedout_date` LIKE '%2015-03-03%'

Answer 1

WHERE子句应在JOIN之后：

SELECT * 
FROM `breaks` JOIN 
     `clock_in_out` ON `breaks`.`user_id` = `clock_in_out`.`user_id`
WHERE `user_id` = 1 
  AND `in_date` LIKE '%2015-03-03%' 
  AND `out_date` LIKE '%2015-03-03%' 
  AND `loggedin_date` LIKE '%2015-03-03%' 
  AND `loggedout_date` LIKE '%2015-03-03%'

Answer 2

您不能混用WHERE和JOIN条款。订单为：SELECT，FROM，JOIN，WHERE，GROUP BY，HAVING，LIMIT。所以它应该是：

SELECT * 
FROM `breaks` 
JOIN `clock_in_out` ON `breaks`.`user_id` = `clock_in_out`.`user_id` 
WHERE `user_id` = 1 
AND `in_date` LIKE '%2015-03-03%' 
AND `out_date` LIKE '%2015-03-03%' 
AND `loggedin_date` LIKE '%2015-03-03%' 
AND `loggedout_date` LIKE '%2015-03-03%'

有关完整语法，请参阅MySQL documentation。

Answer 3

你的语法错了。加入的正确语法是Select ... from .. join ... on ... where

SELECT * 
FROM `breaks` 
JOIN `clock_in_out` ON `breaks`.`user_id` = `clock_in_out`.`user_id` 
WHERE `loggedin_date` 
LIKE '%2015-03-03%' 
AND `loggedout_date` LIKE '%2015-03-03%'
AND `user_id` = 1 
AND `in_date` LIKE '%2015-03-03%' 
AND `out_date` LIKE '%2015-03-03%'

Answer 4

正确的语法如下

    SELECT * 
FROM `breaks` 
JOIN `clock_in_out` ON `breaks`.`user_id` = `clock_in_out`.`user_id` 
WHERE `user_id` = 1 
AND `in_date` LIKE '%2015-03-03%' 
AND `out_date` LIKE '%2015-03-03%' 
AND `loggedin_date` LIKE '%2015-03-03%' 
AND `loggedout_date` LIKE '%2015-03-03%

这个MySQL连接查询有什么问题

4 个答案: