如何将 spring data mongo @CompoundIndex 与子集合一起使用? [英] How to use spring data mongo @CompoundIndex with sub collections?

问题描述

假设我有如下实体:

@Document(collection = "doc_a")
public class A {    
  @Field("id")
  private Integer id;

  @Field("b")
  private Collection<B> b;
  ...
}


public class B {    
  @Field("id")
  private Integer id;
  ...
}

是否可以同时使用关于 A.id 和 B.id 的复合索引?

is it possible to use a compoundIndex with respect to A.id AND B.id together?

我的意思可能是这样的:

I mean maybe like:

@CompoundIndex(name = "aid_bid_idx", def = "{'id', 'b.id'}")

提前致谢.

推荐答案

我已经在我的应用程序中尝试过这种复合索引，它也使用了 spring 数据，并且工作正常.您只需要更正 @CompoundIndex 注释中的索引定义:

I've tried this kind of compound index in my app, that use spring data too, and worked properly. You only have to correct the index definition in @CompoundIndex annotation:

@CompoundIndex(name = "aid_bid_idx", def = "{'id' : 1, 'b.id' : 1}")
@Document(collection = "doc_a")
public class A {    
  @Field("id")
  private Integer id;

  @Field("b")
  private Collection<B> b;
  ...
}

public class B {    
  @Field("id")
  private Integer id;
  ...
} 

如果您在 mongo shell 中使用 explain(如下所示)运行查询，您会看到将使用索引 *aid_bid_idx*.

If you run a query with explain (like the follows) in mongo shell, you'll see that the index *aid_bid_idx* will be used.

db.doc_a.find({ "id" : 1, "b.id" : 1}).explain()

结果会是这样的:

{
    "cursor" : "BtreeCursor aid_bid_idx",
    ...
}

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