MySQL SELECT 从哪里加入

Question

我想从我的数据库中选择一行并加入该行。

当我使用这个命令时它工作正常：

SELECT p.* FROM pages AS p
JOIN products AS pro ON pro.page_id = p.id

但是在执行以下命令时出现错误：

select p.* from pages as p where p.id = 21605
join products as pro on pro.page_id = p.id

为什么会这样，我怎样才能将结果传递给第二个命令？

Answer 1

你的语法不正确

SELECT p.* FROM pages AS p
JOIN products AS pro 
ON pro.page_id = p.id
WHERE p.id = 21605

或

SELECT T.* 
FROM (SELECT p.* FROM pages AS p WHERE p.id = 21605) AS T
JOIN products AS pro 
ON pro.page_id = T.id

MySQL SELECT FROM WHERE JOIN