Unwanted 'AS' when constructing HAVING clause

Hi!

When I use my peewee.Func object, which has _alias, in having(…), then Peewee adds keyword ‘AS’ in clause.

For example:

field = fn.Count(SystemUser.id).alias('roles_count')
query = query.having(field == 2)

Then I get syntax error:

…name" HAVING ((Count(“t1”.“id”) AS roles_count…

I construct queries automatically from rest-requests, so I need to take fields from query.get_query_meta()[0] for comparing with requests and constructing query.

It is easy just clean _alias before constructing query and problem will go away, but nevertheless I think that it is strange behavior.

Thanks for attention!

[coleifer]

This “problem” has been present in peewee since at least version 2.0.0, and at present, exists in the 3.0 rewrite (which you can see here).

The typical way to handle this is to either:

1. Store the unaliased SQL entity in a variable and only call alias() when you need to.
2. Use SQL() object to reference the alias directly.

Example 1:

# Sort users by number of tweets composed, when that number is less than 10
count = fn.COUNT(Tweet.id)
query = (User
        .select(User, count.alias('tweet_count'))
        .join(Tweet, JOIN.LEFT_OUTER)
        .group_by(User)
        .having(count < 10)
        .order_by(count))

Example 2:

# Sort users by number of tweets composed, when that number is less than 10
count = fn.COUNT(Tweet.id).alias('tweet_count')
count_ref = SQL('tweet_count')
query = (User
        .select(User, count.alias('tweet_count'))
        .join(Tweet, JOIN.LEFT_OUTER)
        .group_by(User)
        .having(count_ref < 10)
        .order_by(count_ref))

[coleifer]

This is fixed by e88dbf5145261890bc1a55a2f24ce6dfba36d8db in the 3.0a branch.