python - 将字符串变量传递给 gql 查询

Question

我到底如何使用 python 将字符串变量传递给 GQL？我可以在 SQL 中做的很好，但它只是不工作。这是我所拥有的：

personalposts = db.GqlQuery("select * from PersonalPost where user_id = %s order by created desc limit 30" % user_id)

这一直在杀死我，但我觉得应该很简单。

谢谢！

Answer 1

这应该有效：

personalposts = db.GqlQuery("select * from PersonalPost where user_id =:1 order by created desc limit 30",user_id)

GqlQuery语法示例：

q = GqlQuery("SELECT * FROM Song WHERE composer = 'Lennon, John'")

q = GqlQuery("SELECT __key__ FROM Song WHERE composer = :1", "Lennon, John")

q = GqlQuery("SELECT * FROM Song WHERE composer = :composer", composer="Lennon, John")

来源： https ://developers.google.com/appengine/docs/python/datastore/gqlqueryclass

Answer 2

参数可以通过位置或名称绑定，请查看GqlQuery类文档以获取更多信息。

所以你可以做

personalposts = db.GqlQuery("select * from PersonalPost where user_id = :1 order by created desc limit 30", user_id)

或者

personalposts = db.GqlQuery("select * from PersonalPost where user_id = :id order by created desc limit 30", id = user_id)

Answer 3

创建一个这样的查询：

query = PersonalPost.all()
query.filter('user_id', user_id)
query.order('-created')

或使用：在 '%s' 周围加上单引号 !!

personalposts = db.GqlQuery("select * from PersonalPost where user_id = '%s' order by created desc" % user_id)