如何在Morphia / MongoDB Java中創建復合唯一索引？

Question

假設我有一個MongoDB實體，如下所示：

@Entity(value = "car")
public class Car {
   public String manufacturer;
   public String model;
   public String year;
   public Double price;
}

我想添加一個索引，使得對manufacturer,model,year是獨一無二的。

當我嘗試以下注釋 - @Indexes(@Index(value="manufacturer,model,year, unique=true)) - 它可以工作。但它會引發以下錯誤：

[WARN] (main) : DatastoreImpl - This index on 'Car' is using deprecated configuration options.  Please update to use the fields value on @Index: @org.mongodb.morphia.annotations.Index(unique=true, dropDups=false, background=false, name=, value=manufacturer, model, year, expireAfterSeconds=-1, disableValidation=false, sparse=false, fields=[], options=@org.mongodb.morphia.annotations.IndexOptions(unique=false, dropDups=false, background=false, name=, expireAfterSeconds=-1, disableValidation=false, language=, languageOverride=, sparse=false))

如何正確配置索引？

Answer 1

請嘗試以下注釋

@Entity(value = "car")
@Indexes(@Index(fields = { @Field("manufacturer"), @Field("model"), @Field("year") }, options = @IndexOptions(unique = true)))
public class Car {
   public String manufacturer;
   public String model;
   public String year;
   public Double price;
}