CODEWITHSUNDEEP
pythonsqloracle-databasesqlalchemy
Lev
Lev

Reputation: 1009

SQLAlchemy passing null to or

In SQL if I provide a v_category="fiction" then it would return all fiction books, if we provide v_category=null then it would provide books from all categories:

select * from book where category = :v_category or :v_category is null

How do I do this in SQLAlchemy:

books = Book.query.filter(or_(category = v_category, v_category is None).all()

However since or_ only accepts arguments and not conditions, it throws an error: 

".filter(or_(workscope = v_workscope, v_workscope is None))                                        ^
SyntaxError: positional argument follows keyword argument"

Upvotes: 0

Views: 77

Answers (1)

Ishan Joshi
Ishan Joshi

Reputation: 525

I think if your v_category is null, you should not filter by category.is_(None). By doing so, you would be return all the books with Category as NULL. As per your question, if v_category is None, you want to return all the books of all the categories.

You can try the following code:

def get_book_by_category(v_category):
    query = Book.query
    if v_category:
         query = query.filter(category == v_category)
    return query

Upvotes: 1

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