How to count the object number instead of getting all object in Ruby?

Question

For Example, I want to know the User have how many post. So, I do it in this way;

user.posts.length

It works, but when I see the server log, it shows me that:

SELECT * FROM "posts" WHERE ("posts".user_id = 6)

actually, I need to know the post number only, how can I do this? Thank you.

Swanand · Accepted Answer · 2010-07-14 07:59:44Z

3

user.posts.count

# This will generate this:
SELECT count(*) AS count_all FROM `posts` WHERE (`posts`.user_id = 1)

answered Jul 14, 2010 at 7:59

Swanand

12.4k7 gold badges48 silver badges62 bronze badges

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

Comments

Andrea Pavoni · Accepted Answer · 2010-07-14 08:01:58Z

1

try this:

 user.posts.count

answered Jul 14, 2010 at 8:01

Andrea Pavoni

5,3212 gold badges32 silver badges44 bronze badges

Slobodan Kovacevic · Accepted Answer · 2010-07-14 08:03:12Z

0

You can use count/size method instead of length:

user.posts.count

It will execute query similar to:

SELECT COUNT(*) AS count_id FROM "posts" WHERE ("posts".user_id = 6)

answered Jul 14, 2010 at 8:03

6,8983 gold badges32 silver badges33 bronze badges