根据从另一表中选择的结果从一个表中选择

Question

I'm trying to return rows from one table, based on the results of a select from another table, but I'm not well versed in SQL/Oracle and am struggling to link the two together.

ITEMS                 DEFS
item_id (1000)        trans (1125)
item_state (Y)        desp (680)
trans (1125)
orig_trans (1100)

Overall, I'm trying to query the defs.desp number, and return items.item_id, items.item_state and items.orig_trans, but I can't tell if I need a join or a subquery (or if what I'm trying to achieve is even possible in the first place!)

What I'd like is something like:

SELECT I.ITEM_ID, I.ITEM_STATE, I.ORIG_TRANS
FROM ITEMS I
JOIN DEFS DF
ON I.TRANS = (*FIND 'TRANS' FROM DEFS TABLE USING THE DESP NUMBER BELOW*)
WHERE DF.DESP = 680

And the final desired output being:

ITEM_ID    ITEM_STATE    ORIG_TRANS
1000       Y             1100

The order in which things are returned is what's throwing me, since my final output needs to be from the ITEMS table, but the first thing I need to find out is the TRANS number from the DEFS table?

Answer 1

Isn't it what you need?

SELECT I.ITEM_ID, I.ITEM_STATE, I.ORIG_TRANS
FROM ITEMS I
JOIN DEFS DF
ON I.TRANS = DF.TRANS
WHERE DF.DESP = 680

Answer 2

Try:

SELECT I.ITEM_ID, I.ITEM_STATE, I.ORIG_TRANS
FROM ITEMS I
JOIN (
SELECT TRANS FROM DEFS WHERE DESP = 680
) DF
ON I.TRANS = DF.TRANS

Answer 3

You can try below SQL

SELECT ITEM_ID, ITEM_STATE, ORIG_TRANS FROM ITEMS WHERE TRANS IN ( SELECT TRANS FROM DEFS WHERE DESP = 680 );