Get count of ids

Question

I have a table images - foo_id isn't a key, can have more than one row with the same number.
How do I count the rows with different values for foo_id?

images:

id (int) | foo_id (int) | ...

Example:

0 | 1 | ... 0 | 2 | ... 0 | 3 | ... 0 | 1 | ...

Wanted result:
3

Uli Köhler · Accepted Answer · 2014-01-12 17:00:30Z

1

Use SELECT COUNT(DISTINCT ...)

SELECT COUNT(DISTINCT foo_id) FROM images

Also see http://www.w3schools.com/sql/sql_func_count.asp, several variants of the COUNT statement (including the COUNT(DISTINCT ...) syntax you need in your case are described there)

edited Jan 12, 2014 at 17:00

answered Jan 12, 2014 at 16:51

Uli Köhler

13.9k17 gold badges75 silver badges127 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Lucas Over a year ago

SELECT COUNT(DISTINCT ..) instead SELECT DISTINCT COUNT(id) - well. Thank you, will be accepted asap.

Uli Köhler Over a year ago

Happy to help :) SELECT DISTINCT COUNT can't work because you'd select a COUNT first (yielding one result), and then DISTINCTing it (yielding exactly the same count).

Collectives™ on Stack Overflow

Get count of ids

1 Answer 1

2 Comments

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Related