sqlalchemy 中filter和filter_by区别

filter(*criterion)

apply the given filtering criterion to a copy of this Query, using SQL expressions.

e.g.:

session.query(MyClass).filter(MyClass.name == 'some name')

Multiple criteria may be specified as comma separated; the effect is that they will be joined together using the and_() function:

session.query(MyClass).\    filter(MyClass.name == 'some name', MyClass.id > 5)

The criterion is any SQL expression object applicable to the WHERE clause of a select. String expressions are coerced into SQL expression constructs via the text() construct.

See also

Query.filter_by() - filter on keyword expressions.

filter_by(**kwargs)

apply the given filtering criterion to a copy of this Query, using keyword expressions.

e.g.:

session.query(MyClass).filter_by(name = 'some name')

Multiple criteria may be specified as comma separated; the effect is that they will be joined together using the and_() function:

session.query(MyClass).\    filter_by(name = 'some name', id = 5)

The keyword expressions are extracted from the primary entity of the query, or the last entity that was the target of a call to Query.join().

See also

Query.filter() - filter on SQL expressions.

从外表看的话，主要是写法不同
实质区别在于filter_by只能使用等号，应该更快，可以走索引
filter可以使用>，<取一定范围信息。