如何按年度过滤sqlalchemy中的查询（日期时间列）

Question

I have table in sqlalchemy 0.4 that with types.DateTime column:

Column("dfield", types.DateTime, index=True)

I want to select records, that has specific year in this column, using model. How to do this? I though it should be done like this:

selected_year = 2009
my_session = model.Session()
my_query = my_session.query(model.MyRecord).filter(model.dfield.??? == selected_year)

# process data in my_query

Part with ??? is for me unclear.

Answer 1

sqlalchemy.extract('year', model.MyRecord.dfield) == selected_year

对于referene： https ：//docs.sqlalchemy.org/en/13/core/sqlelement.html#sqlalchemy.sql.expression.extract