When working with data in an SQL database, it's often necessary to filter specific fields to retrieve targeted information. In this case, we explore how to filter a field representing dates using SQLAlchemy.
Given the following model:
class User(Base): ... birthday = Column(Date, index=True) #in database it's like '1987-01-17' ...
Our goal is to filter users based on their birthdays, specifically those within a particular age range, e.g., between 18 and 30 years.
Originally, you attempted to implement the filtering using:
query = DBSession.query(User).filter( and_(User.birthday >= '1988-01-17', User.birthday <= '1985-01-17') )
However, this query is incorrect due to a typo. The proper filter should be:
qry = DBSession.query(User).filter( and_(User.birthday <= '1988-01-17', User.birthday >= '1985-01-17') )
Another alternative for filtering date ranges is the between function:
qry = DBSession.query(User).filter(User.birthday.between('1985-01-17', '1988-01-17'))
By utilizing these filtered queries, you can retrieve specific user records based on their dates of birth, enabling you to perform further operations or analysis on the selected data.
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