我写了一个查询,从出生日期字段开始计算出一个人的年龄,然后使用 AS age
创建一个年龄字段。
我的问题是,是否可以再次匹配那个年龄字段?
像这样,
SELECT `candidates`.`candidate_id`,
`candidates`.`first_name`,
`candidates`.`surname`,
`candidates`.`DOB`,
`candidates`.`gender`,
DATE_FORMAT(NOW(), '%Y') - DATE_FORMAT(`candidates`.`DOB`, '%Y') - (DATE_FORMAT(NOW(), '00-%m-%d') < DATE_FORMAT(`candidates`.`DOB`, '00-%m-%d')) AS `age`
FROM `candidates`
WHERE `age` <= 20
如有任何帮助,我们将不胜感激?
-----所以我将 WHERE 更改为 HAVING,这是我的完整查询------
SELECT `candidates`.`candidate_id`,
`candidates`.`first_name`,
`candidates`.`surname`,
`candidates`.`DOB`,
`candidates`.`gender`,
`candidates`.`talent`,
`candidates`.`location`,
`candidates`.`availability`,
`candidate_assets`.`url`,
`candidate_assets`.`asset_size`
FROM `candidates`
LEFT JOIN `candidate_assets` ON `candidate_assets`.`candidates_candidate_id` = `C`.`candidate_id`
WHERE `C`.`availability` = 'yes'
AND C.talent = "actor"
AND C.skill = "accents"
AND C.gender = "male"
AND HAVING DATE_FORMAT(NOW(), '%Y') - DATE_FORMAT(`candidates`.`DOB`, '%Y') - (DATE_FORMAT(NOW(), '00-%m-%d') < DATE_FORMAT(`candidates`.`DOB`, '00-%m-%d')) <= 69
AND HAVING DATE_FORMAT(NOW(), '%Y') - DATE_FORMAT(`candidates`.`DOB`, '%Y') - (DATE_FORMAT(NOW(), '00-%m-%d') < DATE_FORMAT(`candidates`.`DOB`, '00-%m-%d')) <=19
AND HAVING DATE_FORMAT(NOW(), '%Y') - DATE_FORMAT(`candidates`.`DOB`, '%Y') - (DATE_FORMAT(NOW(), '00-%m-%d') < DATE_FORMAT(`candidates`.`DOB`, '00-%m-%d')) <=49
我得到以下错误,
You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'HAVING DATE_FORMAT(NOW(), '%Y') - DATE_FORMAT(candidates
.DOB
, '%Y') - (DATE_' at line 15
我这辈子都不知道它是什么。
一种方法是将原始查询包装为子查询,并将 WHERE
子句移动到外部查询:
SELECT * FROM (
SELECT `candidates`.`candidate_id`, -- this is the original query
`candidates`.`first_name`,
`candidates`.`surname`,
`candidates`.`DOB`,
`candidates`.`gender`,
DATE_FORMAT(NOW(), '%Y') - DATE_FORMAT(`candidates`.`DOB`, '%Y') - (DATE_FORMAT(NOW(), '00-%m-%d') < DATE_FORMAT(`candidates`.`DOB`, '00-%m-%d')) AS `age`
FROM `candidates` ) as innertable
WHERE `age` <= 20 -- this is now part of the outer query
澄清:这在 MySQL 5 中有效
注意:这假定原始查询有效
Tôi là một lập trình viên xuất sắc, rất giỏi!