mongos> var it = db.test.find({'i': 1, "old_id": {$exists: 1}}) 遍历计数1:mongos> var count = 0;while(it.hasNext()){if (it.next()["X"].length==32)++count}print(count) 遍历计数2:mongos> var count = 0;while(it.hasNext()){var item = it.next(); if (item['X']...
Index Filters决定了优化器将为query shape评价那个索引,如果Index Filters中包含了该Index Filters,优化器将仅考虑执行Index Filters指定的索引(When an index filter exists for the query shape, MongoDB ignores thehint(). To see whether MongoDB applied an index filter for a query shape, check theindexFi...
Caused by: com.mongodb.MongoCommandException: Command failed with error 85: 'exception: Index with name: deviceId already exists with different options' on server 127.0.0.1:27017. The full response is { "createdCollectionAutomatically" : false, "numIndexesBefore" : 6, "errmsg" : "exception: ...
Optional. Sets whether sync creates a supporting index for the shard key, if none exists. The default isfalse. For more information and limitations, seeSupporting Indexes. shardingEntries array of documents Required. Sets the namespace and key of collections to shard during sync. ...
"indexName" : <string>, "recordId" : <NumberLong>, "idKey" : <_id key value>, // The _id value of the document. Only present if an ``_id`` index exists. "indexKey" : { // The missing index entry "<key1>" : <value>, ... } } ... ] 注意 For the missingIndexEntries...
操作符效果 $exists 存在与否 $or 或者 $and 并且 $not 不存在 $mod 求模 $where 位置特别的 $exists: true 表示字段存在排序sort 操作效果 $asc 升序 $desc 降序3、更新文档 更新文档有两种方式进行修改 方法一、直接修改 db.集合名.update({条件},{新的文档}) :修改当前数据库下指定集合中满足条...
Command failed with error85:'exception: Index with name: deviceId already exists with different options'on server127.0.0.1:27017. The full responseis{"createdCollectionAutomatically":false,"numIndexesBefore":6,"errmsg":"exception: Index with name: deviceId already exists with different options","co...
aggregate,checkShardingIndex,cloneCollectionAsCapped,collStats,count,dataSize,dbHash,dbStats,distinct,filemd5,mapReduce(inline output only),text(beta feature)geoNear,geoSearch,geoWalk,group; B:readWrite:数据库的读写权限,包含read角色的所有权限,包括如下: ...
("Index created successfully");// Check if the index existscollection.indexExists({field1:1,field2:-1},function(err,result){if(err){console.error(err);return;}if(result){console.log("Index created successfully");}else{console.log("Index creation failed");}// Close the connectionclient....
<cfscript> bucket = getmongoservice("mymongodb").db("newdb").createbucket("bucket") try{ res = bucket.drop() if(res.name == "bucket"){ writeoutput("Bucket is deleted successfully") } } catch(any e){ writeDump(e) } </cfscript> Index methods db.collection.createIndex This functio...