内部连接中的mysql语法错误

Question

I am trying to perform a query with inner join and adding a where but I get the following error:

1064 - 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 'where orders.user_id = 31)

And the query is structured in this way:

SELECT
    orders.id,
    order_details.order_id,
    orders.user_id,
    orders.numero_orden,
    order_details.part_id,
    order_details.cantidad
FROM
((orders
    INNER JOIN order_details
        ON orders.id = order_details.order_id
    where orders.user_id = 31) 
INNER JOIN parts
    ON order_details.part_id  = parts.id);

Answer 1

Your query looks like you are trying to use MS Access syntax. In MySQL, you don't need to wrap components of a multiple join with parentheses. Consider this version:

SELECT
    o.id,
    od.order_id,
    o.user_id,
    o.numero_orden,
    od.part_id,
    od.cantidad
FROM orders o
INNER JOIN order_details od
    ON o.id = od.order_id
INNER JOIN parts p
    ON od.part_id  = p.id
WHERE
    o.user_id = 31;

Notes: I refactored your query to use table aliases, leaving it much easier to read. Also, I don't really see the point of joining to the parts table, because you never select anything from it. Perhaps you intended to do that, but it did not make it into your question.

Answer 2

You can't put the WHERE clause there, it needs to be at the end, or you could try leaving it where it is and replacing the WHERE with an AND to make it part of the join clause. I think the result will be the same.

So either:

SELECT
    orders.id,
    order_details.order_id,
    orders.user_id,
    orders.numero_orden,
    order_details.part_id,
    order_details.cantidad
FROM
    orders
    INNER JOIN order_details
        ON orders.id = order_details.order_id
    INNER JOIN parts
        ON order_details.part_id  = parts.id
WHERE 
    orders.user_id = 31;

or

SELECT
    orders.id,
    order_details.order_id,
    orders.user_id,
    orders.numero_orden,
    order_details.part_id,
    order_details.cantidad
FROM
    orders
    INNER JOIN order_details
        ON orders.id = order_details.order_id
           AND orders.user_id = 31
    INNER JOIN parts
        ON order_details.part_id  = parts.id;

Not sure you really need those brackets round the joins either, so I removed them. I would recommend that maybe you should study the allowed syntax for a SQL query in more detail to understand about where you need to place the different parts.