Flask SQLAlchemy查询，指定列名 [英] Flask SQLAlchemy query, specify column names

问题描述

如何使用模型在查询中指定所需的列(默认情况下会选择所有列)?我知道如何在sqlalchmey会话中执行此操作:session.query(self.col1)，但是如何在模型中执行此操作?我不能做SomeModel.query().有办法吗?

How do I specify the column that I want in my query using a model (it selects all columns by default)? I know how to do this with the sqlalchmey session: session.query(self.col1), but how do I do it with with models? I can't do SomeModel.query(). Is there a way?

推荐答案

您可以使用with_entities()方法来限制要在结果中返回的列. (文档)

You can use the with_entities() method to restrict which columns you'd like to return in the result. (documentation)

result = SomeModel.query.with_entities(SomeModel.col1, SomeModel.col2)

根据您的要求，您还可能会找到

Depending on your requirements, you may also find deferreds useful. They allow you to return the full object but restrict the columns that come over the wire.

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