complicated SQL for MySQL - 07-18-2004 , 06:01 AM
If I a user table and a item table has - in both a incremental value
is led (ID) - and I beside it in an order table all sales the user
lead, how I can all items to be indicated be able, which were not
bought of usern yet?
A beginning is:
SELECT DISTINCT * FROM items WHERE items.itemID EMERGENCY IN (SELECT
items.itemID FROM orders)
And as I bring the user purely?
Sea the following result:
user1 buys item1 and item2
user2 buys item3 and item1
result of the looked for SQL inquiry
item2 (not bought of user2)
item3 (not bought of user1)
The following solution brings to NULL as soon as more than one user
existed and both different things bought, together regards it however
everything bought (desire result quantity)
SELECT * FROM items i LEFT JOIN orders o ON (o.itemID = i.itemID) LEFT
JOIN users u ON (u.userID = o.userID) WHERE i.itemID IS NULL
possibly who has any idea?