pythonsqlalchemy

group by year, month, day in a sqlalchemy


I want

DBSession.query(Article).group_by(Article.created.month).all()

But this query can't using

How do I do this using SQLAlchemy?


Solution

  • assuming you db engine actually supports functions like MONTH(), you can try

    import sqlalchemy as sa
    DBSession.query(Article).group_by( sa.func.year(Article.created), sa.func.month(Article.created)).all()
    

    else you can group in python like

    from itertools import groupby
    
    def grouper( item ): 
        return item.created.year, item.created.month
    for ( (year, month), items ) in groupby( query_result, grouper ):
        for item in items:
            # do stuff