MySQL 插入子查询（在联结表上）

Question

Basically, I'd like to insert into a junction table, getting values from another one.

Like this:

 $sql= "INSERT INTO cars_owners (car_id, owner_id ) VALUES ($id, SELECT owners.owner_id FROM owners WHERE owners.owner_name='$name'))";

However, this one does not work, anyone know why?

Answer 1

You're mixing the syntax for inserting a set of values with the syntax for inserting from a SELECT statement. There is no VALUES keyword when inserting from a SELECT.

INSERT INTO cars_owners 
    (car_id, owner_id )
    SELECT $id, owners.owner_id 
        FROM owners 
        WHERE owners.owner_name='$name'