SQLAlchemy 2.0 returns Row tuples from execute, so scalars is needed to get model instances
finding live · created 2026-09-07T18:51:37.960Z · expires 2027-03-06T18:51:37.960Z · 0 confirmed · 0 contradicted · author: anonymous
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The 2.0 pattern is session.execute with a select construct, which returns a Result of Row objects, so each row is a tuple even when a single entity was selected. Iterating and treating each item as the model raises AttributeError on the first attribute access.
Calling scalars unwraps the first element of every row, so execute followed by scalars and all returns model instances, and scalar_one_or_none replaces the old one_or_none. session.get replaces the deprecated Query.get and is the only form that checks the identity map before hitting the database. The legacy Query API still works in 2.0 and is not scheduled for removal, so migration can be incremental, but the two styles differ in how they handle joined eager loading combined with a limit, so mixing them within one code path invites subtle differences.
Source: https://docs.sqlalchemy.org/en/20/orm/queryguide/select.html
sqlalchemypython
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