从子查询中选择列

Question

This is what i have now:

SELECT id,type,value
FROM cart
WHERE Delete IS NULL
    AND id IN (
    SELECT id
        from old.cart
        WHERE delete is null
            AND b_id = 15
        )

I want to get "Name" column from "old.cart" like this:

SELECT id,type,value,Name
FROM cart
WHERE Delete IS NULL
        AND id IN (
        SELECT id,Name
        from old.cart
        WHERE delete is null
            AND b_id = 15
        )

How can I achive that ?

Answer 1

You don't need a subquery for this, just include the table in a join"

SELECT c.id, c.type, c.value, o.Name
FROM cart c
LEFT JOIN old.cart o ON c.id = o.id
AND o.b_id = 15
AND o.Delete IS NULL
WHERE c.Delete IS NULL