Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
722 views
in Technique[技术] by (71.8m points)

sql - PostgreSQL, SELECT from max id

By using libpq on PG 9.1, I am trying to write query to get values from row with highest index 'my_id':

SELECT my_id, col2, col3 
FROM mytable 
WHERE my_id = MAX(my_id)

That gives me error:

ERROR: aggregates not allowed in WHERE clause...

How to write such query properly?

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Answer

0 votes
by (71.8m points)

If your goal is to get the row with the highest my_id value, then the following query should achieve the same goal.

SELECT my_id, col2, col3 
FROM mytable 
ORDER BY my_id DESC 
LIMIT 1

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome to OStack Knowledge Sharing Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...