Difference between filter and filter by in SQLAlchemy

Question

Could anyone explain the difference between filter and filter by functions in SQLAlchemy  Which one should I be using

User · Answer

filter by uses keyword arguments  whereas filter allows pythonic filtering arguments like filter User name   john

User · Answer

filter by is used for simple queries on the column names using regular kwargs  like  db users filter by name  Joe    The same can be accomplished with filter  not using kwargs  but instead using the      equality operator  which has been overloaded on the db users name object   db users filter db users name   Joe    You can also write more powerful queries using filter  such as expressions like   db users filter or  db users name   Ryan   db users country   England

User · Answer

We actually had these merged together originally  i e  there was a  filter -like method that accepted  args and   kwargs  where you could pass a SQL expression or keyword arguments  or both    I actually find that a lot more convenient  but people were always confused by it  since they re usually still getting over the difference between column    expression and keyword   expression   So we split them up

User · Answer

It is a syntax sugar for faster query writing  Its implementation in pseudocode   def filter by self    kwargs       return self filter sql and    kwargs     For AND you can simply write   session query db users  filter by name  Joe   surname  Dodson     btw   session query db users  filter or  db users name   Ryan   db users country   England      can be written as   session query db users  filter  db users name   Ryan      db users country   England      Also you can get object directly by PK via get method   Users query get 123    And even by a composite PK Users query get 123  321    When using get case its important that object can be returned without database request from identity map which can be used as cache associated with transaction

[python] Difference between filter and filter_by in SQLAlchemy

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