SQLAlchemy：使用自定义字段和值构建查询(SQLAlchemy: Building query with custom field and value)

SQLAlchemy：使用自定义字段和值构建查询(SQLAlchemy: Building query with custom field and value)

如何将以下SQL查询转换为SQLAlchemy模拟？

SELECT 'custom_value' AS `custom_field`, f.`bar` FROM `Foo` f

'Foo'型号：

from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String Base = declarative_base() class Foo(Base): __tablename__ = 'Foo' id = Column(Integer, primary_key=True) bar = Column(String)

How to convert following SQL query to SQLAlchemy analog?

SELECT 'custom_value' AS `custom_field`, f.`bar` FROM `Foo` f

'Foo' model:

from sqlalchemy.ext.declarative import declarative_base from sqlalchemy import Column, Integer, String Base = declarative_base() class Foo(Base): __tablename__ = 'Foo' id = Column(Integer, primary_key=True) bar = Column(String)

最满意答案

请看这个答案中的第二个例子： https ： //stackoverflow.com/a/3576573/344141

简而言之 - 使用literal("custom_value", type_=Unicode).label('custom_field') ，因此您的查询将如下所示：

session.query(literal("custom_value", type_=Unicode).label('custom_field'), Foo.bar)

Look at second example in this answer: https://stackoverflow.com/a/3576573/344141

In short - use literal("custom_value", type_=Unicode).label('custom_field'), so your query will look like this:

session.query(literal("custom_value", type_=Unicode).label('custom_field'), Foo.bar)