问题描述
我有一份为文档创建新字段的工作，我希望在此工作结束时为该字段创建索引.我尝试过
I have a job that create new fields to my document, I want, at the end of this job, to create indexes to this fields. I tried
Model.index("field"=>-1)
还有
Mongoid::Sessions.default[:rating_prediction].ensureIndex
没有成功
这可能吗?
推荐答案
说 Model.index(:field => -1) 或多或少只是在Model中注册索引的存在，而实际上并没有创建索引.您正在寻找 create_indexes :
Saying Model.index(:field => -1), more or less, just registers the existence of the index with Model, it doesn't actually create an index. You're looking for create_indexes:
将实际的索引创建注释发送到MongoDB驱动程序
Send the actual index creation comments to the MongoDB driver
所以你想说:
Model.index(:field => -1)
Model.create_indexes
您还可以通过调用 create 在集合的 indexes :
You can also create them directly through Moped by calling create on the collection's indexes:
Mongoid::Sessions.default[:models].indexes.create(:field => 1)
Model.collection.indexes.create(:field => 1)
Mongoid::Sessions在较新的版本中已重命名为Mongoid::Clients，因此您可能需要说:
Mongoid::Sessions has been renamed to Mongoid::Clients in newer versions so you might need to say:
Mongoid::Clients.default[:models].indexes.create(:field => 1)
Model.collection.indexes.create(:field => 1)
感谢 js_ 注意此更改.
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