在您的BuildConfig.groovy中放置这个
依赖关系{b / b $ b
compileorg.mongodb：mongo-java-driver：2.10.1 runtime com.gmongo：gmongo：1.1}然后在插件部分 p>
插件{
compile（：mongodb：1.1.0.GA ）{不包括'mongo-java-driver'，'gmongo'} }这会更新您的mongodb插件以使用最新的java驱动程序和gmongo。然后使用聚合框架。例子
DBObject match = new BasicDBObject（'$ match'，new BasicDBObject（adPostId，50））; //建立$投影操作 DBObject fields = new BasicDBObject（adPostId，1）; fields.put（shopperId，1）; fields.put（_ id，0）; DBObject project = new BasicDBObject（'$ project'，fields）; //现在$ group操作 DBObject groupFields = new BasicDBObject（_id，'$ karmaType'）; groupFields.put（average，新的BasicDBObject（'$ sum'，'$ rating'））; DBObject组=新的BasicDBObject（'$ group'，groupFields）; //运行汇总 AggregationOutput输出= db.karma.aggregate（match，project，group）;return [model：[avgkarma：output.getCommandResult（）]]
How can I use Aggregation framework in Grails 1.3.7. At the moment i can't migrate into new version of grails. I have tried grails mongodb plugin 1.0.0.GA but it is using old java driver and gmongo libs. I have also tried to add dependencies for new libs/jars in build-config.groovy but still it is giving me error at runtime for aggregate method. Any help is highly appreciated.
解决方案In your BuildConfig.groovy put this
dependencies {
compile "org.mongodb:mongo-java-driver:2.10.1" runtime "com.gmongo:gmongo:1.1" }And then in plugin section
plugins {
compile (":mongodb:1.1.0.GA"){ excludes 'mongo-java-driver', 'gmongo' } }This will update your mongodb plugin to use the latest java drivers and gmongo.
Then use aggregation framework. Example
DBObject match = new BasicDBObject('$match', new BasicDBObject("adPostId", 50) ); // build the $projection operation DBObject fields = new BasicDBObject("adPostId", 1); fields.put("shopperId", 1); fields.put("_id", 0); DBObject project = new BasicDBObject('$project', fields ); // Now the $group operation DBObject groupFields = new BasicDBObject( "_id", '$karmaType'); groupFields.put("average", new BasicDBObject( '$sum', '$rating')); DBObject group = new BasicDBObject('$group', groupFields); // run aggregation AggregationOutput output = db.karma.aggregate( match, project, group );return [model:[avgkarma:output.getCommandResult()]]
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