Spring data mongodb - 'cursor' 选项是必需的 [英] Spring data mongodb - The 'cursor' option is required

问题描述

我正在尝试使用 Spring Data MongoDB 3.6-rc4 执行聚合操作.

I am trying to execute an aggregate operation using Spring Data MongoDB 3.6-rc4.

Aggregation agg = newAggregation(
    lookup("orders", "orderId", "_id", "order") 
);
List<BasicDBObject> results = mongoOperations.aggregate(agg, "transactions", BasicDBObject.class).getMappedResults();

但是在运行查询时出现以下错误

But get the following error on running the query

2017-11-24 17:03:41,539 WARN  org.springframework.data.mongodb.core.MongoTemplate : Command execution of { "aggregate" : "transactions" , "pipeline" : [ { "$lookup" : { "from" : "orders" , "localField" : "orderId" , "foreignField" : "_id" , "as" : "order"}}]} failed: The 'cursor' option is required, except for aggregate with the explain argument
2017-11-24 17:03:41,574 ERROR org.apache.catalina.core.ContainerBase.[Tomcat].[localhost].[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.InvalidDataAccessApiUsageException: Command execution failed:  Error [The 'cursor' option is required, except for aggregate with the explain argument], Command = { "aggregate" : "transactions" , "pipeline" : [ { "$lookup" : { "from" : "orders" , "localField" : "orderId" , "foreignField" : "_id" , "as" : "order"}}]}; nested exception is com.mongodb.MongoCommandException: Command failed with error 9: 'The 'cursor' option is required, except for aggregate with the explain argument' on server localhost:27017. The full response is { "ok" : 0.0, "errmsg" : "The 'cursor' option is required, except for aggregate with the explain argument", "code" : 9, "codeName" : "FailedToParse" }] with root cause
com.mongodb.MongoCommandException: Command failed with error 9: 'The 'cursor' option is required, except for aggregate with the explain argument' on server localhost:27017. The full response is { "ok" : 0.0, "errmsg" : "The 'cursor' option is required, except for aggregate with the explain argument", "code" : 9, "codeName" : "FailedToParse" }
    at com.mongodb.CommandResult.getException(CommandResult.java:80) ~[mongo-java-driver-3.5.0.jar:na]
    at com.mongodb.CommandResult.throwOnError(CommandResult.java:94) ~[mongo-java-driver-3.5.0.jar:na]
    at org.springframework.data.mongodb.core.MongoTemplate.handleCommandError(MongoTemplate.java:2100) ~[spring-data-mongodb-1.10.8.RELEASE.jar:na]
    at org.springframework.data.mongodb.core.MongoTemplate.aggregate(MongoTemplate.java:1577) ~[spring-data-mongodb-1.10.8.RELEASE.jar:na]
    at org.springframework.data.mongodb.core.MongoTemplate.aggregate(MongoTemplate.java:1505) ~[spring-data-mongodb-1.10.8.RELEASE.jar:na]

提前致谢！！

推荐答案

MongoDB 在 3.6 中更改了聚合命令的工作方式.聚合现在需要一个游标.我们调整了 Spring Data MongoDB 2.1，但没有调整以前的版本.

MongoDB changed in 3.6 how the aggregation command works. Aggregations require now a cursor. We adapted Spring Data MongoDB 2.1 but not previous versions.

必须通过集合的 aggregate(…) 方法调用聚合，而不是直接调用命令.这也是我们没有向后移植更改的原因.executeCommand(...) 不再被调用，我们不希望在错误修复版本中破坏兼容性.

Aggregations must be invoked through the collection's aggregate(…) method instead of calling the command directly. This is also the reason why we didn't backport the change. executeCommand(…) is no longer called and we don't want to break compatibility in a bugfix release.

最简单的方法是覆盖 aggregate(…) 方法并使用映射的聚合管道调用适当的方法 DBCollection.aggregate(…).

The easiest approach for you can be to override the aggregate(…) method and call the appropriate method, DBCollection.aggregate(…) with the mapped aggregation pipeline.

这篇关于Spring data mongodb - 'cursor' 选项是必需的的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！