Unknown column in where clause. Why?

Question

I use next query:

SELECT ROUND(r/h) AS conv FROM table WHERE conv > 1

I receive error "Unknown column 'conv' in 'where clause'", But why? After AS conv is it not exists yet?

@Bob's answer shows correct approach, through you may like to try: `SELECT * FROM (SELECT ROUND(r/h) AS conv FROM table) as t1 WHERE conv > 1;` — Grijesh Chauhan, Mar 22 '14 at 13:10

score 3 · Accepted Answer · answered Mar 22 '14 at 13:04

3

The column alias isn't available until results are being produced. Try

SELECT ROUND(R / H) AS CONV
  FROM TABLE1
  WHERE ROUND(R / H) > 1

Share and enjoy.

answered Mar 22 '14 at 13:04

After reading your answer, my answer looks Jok. – Grijesh Chauhan Mar 22 '14 at 13:08

1 Answers1