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(默认情况下它会选择所有列)?我知道如何使用 sqlalchmey 会话执行此操作:session.query(self.col1)，但是我如何使用模型执行此操作?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() 方法来限制您希望在结果中返回哪些列.(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)

根据你的要求，你还可以找到延迟很有用.它们允许您返回完整的对象，但限制通过网络的列.

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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