有必要将两个查询合并为一个

Question

MySQL有两个数据库查询：

1）SELECT id, username, subject, message, created FROM messages WHERE new = 1 AND view = '$ auth_user'

2）SELECT DATE_FORMAT (created, '% d% M% Y% T') FROM messages

您能告诉我如何将它们合并到一个SQL查询中吗？

Answer 1

你去了：

SELECT id, username, subject, message, created, DATE_FORMAT (created, '% d% M% Y% T') FROM messages WHERE new = 1 AND view = '$auth_user'

但请记住，您的第二个查询会从您的表中返回所有消息日期。您的第一个查询会返回包含属性new = 1和view = $auth_user的所有邮件。

编辑：

SELECT id, username, subject, message, DATE_FORMAT (created, '% d% M% Y% T') AS created FROM messages WHERE new = 1 AND view = '$auth_user'

Answer 2

SELECT id, username, subject, message, created, DATE_FORMAT (created, '% d% M% Y% T')
FROM messages 
WHERE new = 1 AND view = '$auth_user'

现在第二个查询依赖于Where子句