Spring data mongodb - The 'cursor' option is required

Question

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();

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]

Thanks in advance!!

Answer 1

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.

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.

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