Mongo list all fields
With the use of the $ array projection operator, you can specify the projection to return the first element that match the query condition on the array field; e.g. " ... ,switch to the db you're using and type: mr = db.runCommand( "mapreduce" : "myCollectionName", "map" : function() for (var key in this) emit(key, null); } } ...
| 相關軟體 MongoDB 資訊 | |
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 Mongo list all fields 相關參考資料
$all — MongoDB Manual
The $all operator selects the documents where the value of a field is an array that contains all the specified elements. To specify an $all expression, use the ... https://docs.mongodb.com db.collection.find() — MongoDB Manual
With the use of the $ array projection operator, you can specify the projection to return the first element that match the query condition on the array field; e.g. " ... https://docs.mongodb.com Get all fields names in a mongodb collection? - Stack Overflow
switch to the db you're using and type: mr = db.runCommand( "mapreduce" : "myCollectionName", "map" : function() for (var key in this) emit(key, null); } } ...... https://stackoverflow.com Get all fields names in a MongoDB collection? - Tutorialspoint
2019年6月13日 — You can use the concept of Map Reduce. Let us first create a collection with documents −> db.getAllFieldNamesDemo. https://www.tutorialspoint.com Get names of all keys in the collection - Stack Overflow
2012年4月29日 — I'd like to get the names of all the keys in a MongoDB collection. For example, from this: db.things.insert( type : ['dog', 'cat ... https://stackoverflow.com Get the Names of All Keys in a MongoDB Collection ...
2019年1月18日 — In order to validate your schema, debug for typos in fields, or find fields that aren't supposed to be set, you'll need to get an understanding of all ... https://www.objectrocket.com How to select a single field for all documents in a MongoDB ...
2018年3月3日 — In this example from the folks at Mongo, the returned documents will ... inside next curly braces: list of projection field names to be needed in the ... https://stackoverflow.com How to view document fields in mongo shell? - Stack Overflow
2011年5月5日 — start mongo client mongo // ------------ // list all databases show dbs // NOTE: assume one of the databases is myNewDatabase // use the ... https://stackoverflow.com List all values of a certain field in mongodb - Stack Overflow
2014年4月24日 — db.collection.distinct('x'). should give you an array of unique values for that field. https://stackoverflow.com Project Fields to Return from Query — MongoDB Manual
By default, queries in MongoDB return all fields in matching documents. ... index; e.g. "instock.0": 1 } projection will not project the array with the first element. https://docs.mongodb.com |