spring-data-mongodb

问题 I am developing Spring Boot + Spring Data Mongo . I am really struggling to public Page<EmployeeOut> getData(Pageable pageable) { ....... ....... MatchOperation matchStage = Aggregation.match(criteria); GroupOperation groupOp = Aggregation .group("firstName", "lastName", "email", "status", "id") .addToSet("department").as("department").addToSet("address").as("address"); ProjectionOperation projectStage = Aggregation.project("firstName", "lastName", "email", "status", "department", "address",

问题 $arrayElemAt new in MongoDB version 3.2. db.users.aggregate([ { $project: { name: 1, first: { $arrayElemAt: [ "$favorites", 0 ] }, last: { $arrayElemAt: [ "$favorites", -1 ] } } } ]) 回答1: DATAMONGO-1536 is about to add $arrayElemAt and other missing aggregation operators to Spring Data MongoDB for the Ingalls release. Meanwhile you can provide your own AggregationExpression to create whatever operation is needed. For the above something like the following does the trick: project("name") //

问题 $arrayElemAt new in MongoDB version 3.2. db.users.aggregate([ { $project: { name: 1, first: { $arrayElemAt: [ "$favorites", 0 ] }, last: { $arrayElemAt: [ "$favorites", -1 ] } } } ]) 回答1: DATAMONGO-1536 is about to add $arrayElemAt and other missing aggregation operators to Spring Data MongoDB for the Ingalls release. Meanwhile you can provide your own AggregationExpression to create whatever operation is needed. For the above something like the following does the trick: project("name") //

问题 I have a MongoRepository class public interface UserRepository extends MongoRepository<User, Long> { User findById(Long id); } and my Entity pojo looks like this @Document(collection = "user") class User { Long id; String name; Department department; … } When I call the findBy method, a User object is returned. I want to know how does Spring Data MongoDB converts DBObject to Java object. I was under the impression that Spring Data MongoDB uses some sort of mapper (Jackson?) under the hood

问题 I have a MongoRepository class public interface UserRepository extends MongoRepository<User, Long> { User findById(Long id); } and my Entity pojo looks like this @Document(collection = "user") class User { Long id; String name; Department department; … } When I call the findBy method, a User object is returned. I want to know how does Spring Data MongoDB converts DBObject to Java object. I was under the impression that Spring Data MongoDB uses some sort of mapper (Jackson?) under the hood

问题 I have set up my own mechanism for assigning identities to my domain objects, and so when persisting them, there really isn't much value for me to keep track of what MongoDB assigns to them. However, I name the identity fields for my domain classes id because, well, it's concise and understandable. The problem is that, according to the documentation, Spring will automatically map this field to MongoDB's assigned ObjectID. How do I prevent this from happening without having to rename my id

问题 I have set up my own mechanism for assigning identities to my domain objects, and so when persisting them, there really isn't much value for me to keep track of what MongoDB assigns to them. However, I name the identity fields for my domain classes id because, well, it's concise and understandable. The problem is that, according to the documentation, Spring will automatically map this field to MongoDB's assigned ObjectID. How do I prevent this from happening without having to rename my id

问题 I have found several example at StackOverFlow related to addFields in Aggregation. But no one implemented in Java. db.getCollection('myDocument').aggregate([ {$match : {"metaId.ref.uuid" : "d6112808-1ce1-4545-bd52-cf55bc4ed25e"}}, {$lookup: {from: "simple", localField: "someId.ref.uuid", foreignField: "uuid", as: "simple"}}, {"$unwind": "$simple"}, {"$addFields": { "metaId.ref.name" : "$simple.name" }} ]) I am not able to Implement In Java Correctly:-- Not getting proper procedure

问题 I have found several example at StackOverFlow related to addFields in Aggregation. But no one implemented in Java. db.getCollection('myDocument').aggregate([ {$match : {"metaId.ref.uuid" : "d6112808-1ce1-4545-bd52-cf55bc4ed25e"}}, {$lookup: {from: "simple", localField: "someId.ref.uuid", foreignField: "uuid", as: "simple"}}, {"$unwind": "$simple"}, {"$addFields": { "metaId.ref.name" : "$simple.name" }} ]) I am not able to Implement In Java Correctly:-- Not getting proper procedure

问题 com.mongodb.CommandFailureException: { "serverUsed" : "localhost:27017" , "createdCollectionAutomatically" : true , "numIndexesBefore" : 1 , "ok" : 0.0 , "errmsg" : "namespace name generated from index name \"NDS.ABCD_pre_import.$importabilityEvaluations.perNameResults.straightImportResults.resultPolContent_NOT_IN_CURRENT_USE.officialPolResultNameContentId\" is too long (127 byte max)" , "code" : 67} at com.mongodb.CommandResult.getException(CommandResult.java:76) at com.mongodb.CommandResult