Mongodb的Grails聚合框架1.3.7 [英] Mongodb Aggregation framework for grails 1.3.7

问题描述

如何在Grails 1.3.7中使用Aggregation框架。目前我无法迁移到新版本的grails。我已经尝试过grails mongodb plugin 1.0.0.GA，但它使用的是旧的java驱动程序和gmongo库。我也尝试在build-config.groovy中添加新libs / jar的依赖项，但它仍然在运行时给我提供了集合方法的错误。任何帮助的高度赞赏。

解决方案

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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