Question

I have a triple join that looks like this:

   select DATE_FORMAT(Posts.PostDate, '%Y-%m-%d'), (Tags.TagName)
    from Posts
    join PostTags
            on Posts.PK_PostID = PostTags.FK_PostID
        join Tags
            on Tags.PK_TagID = PostTags.FK_TagID
    where Tags.TagName = 'Money'

The result looks like this:

But I want it to be grouped by the date, and then next to it the number of times the tag is used. I can’t figure it out. Something like this:

2012-12-26 10
2012-12-27 4

Answer 1

Without a fiddle, I believe what you want is this:

    select DATE_FORMAT(Posts.PostDate, '%Y-%m-%d'), count(Tags.TagName)
    from Posts
    join PostTags
            on Posts.PK_PostID = PostTags.FK_PostID
        join Tags
            on Tags.PK_TagID = PostTags.FK_TagID
    where Tags.TagName = 'Money'
    group by DATE_FORMAT(Posts.PostDate, '%Y-%m-%d')