Question

Here is my two tables feeds and traders. Now i want to select the rows from both tables where the feed_id of feeds table not in trdr_feed_id of traders table. And here is the structure of both tables.

Feeds

Traders

And this is the join query i’m using.

SELECT * FROM feeds LEFT JOIN traders ON feeds.feed_id = traders.trdr_feed_id

This is the output i’m getting. What i need is, only the rows with the null values. But please note that the columns with the null values should be preserved with the values null.

Any help on this would be greatly appreciated.

Answer 1

try this without JOIN

SELECT  Feed_ID
FROM    Feeds
WHERE   Feed_ID NOT IN
        (
            SELECT trdr_feed_id
            FROM    Traders
        )

or this:

SELECT * 
FROM   Feeds a
          LEFT JOIN Traders b
              ON a.Feed_ID = b.trdr_feed_id
WHERE a.trdr_id IS NULL