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()
$exists {<key>:{$exists:<value>}}字段是否存在。 db.col.find( { item : { $exists: false } } ) 模糊查询 没有操作符,根据书写规则来决定是否是模糊查询。 和普通is查询一样,但是值需要加//。 like:{name:/小/} likeBegin: {name:/^小/} likeEnd:{name:/小^/} db.col.find( { item :...
"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...
collection.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.close();}); 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11...
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 $desc 降序3、更新文档 更新文档有两种方式进行修改 方法一、直接修改 db.集合名.update({条件},{新的文档}) :修改当前数据库下指定集合中满足条...
--bind_ip does not enable ipv6 support. if specifying a link-local ipv6 address ( fe80::/10 ), you must append the zone index to that address (i.e. fe80::%<adapter-name> ). example localhost,fe80::a00:27ff:fee0:1fcf%enp0s3 important to avoid configuration updates due to ip ad...
If a non-TTL single-field index already exists for a field, you cannot create a TTL index on the same field because you cannot create indexes that have the same key specification and differ only by the options. To change a non-TTL single-field index to a TTL index, use the collMod da...
Caused by: com.mongodb.MongoCommandException: Command failed with error 85: 'exception: Index with name: deviceId already exists with different options' on server 127.0.0.1:27017. The full response is { "createdCollectionAutomatically" : false, "numIndexesBefore" : 6, "errmsg" : "exception:...
aggregate,checkShardingIndex,cloneCollectionAsCapped,collStats,count,dataSize,dbHash,dbStats,distinct,filemd5,mapReduce(inline output only),text(beta feature)geoNear,geoSearch,geoWalk,group; B:readWrite:数据库的读写权限,包含read角色的所有权限,包括如下: ...
"Index build: done building","attr":{"buildUUID":null,"namespace":"config.system.sessions","index":"lsidTTLIndex","commitTimestamp":null}} {"t":{"$date":"2022-11-04T01:17:51.161+00:00"},"s":"I", "c":"STORAGE", "id":22430, "ctx":"Checkpointer","msg":"WiredTiger ...