Table of Contents
- 1 How do I add a field to an existing document in MongoDB using Java?
- 2 How do I query a nested field in MongoDB?
- 3 How do I add a field to an existing document in MongoDB using a compass?
- 4 What is sub document in MongoDB?
- 5 How do I edit a field in MongoDB?
- 6 How do I change the field type in MongoDB?
- 7 What is the difference between multimulti and updatemany in MongoDB?
- 8 Is MongoDB schema-free?
How do I add a field to an existing document in MongoDB using Java?
Or in the same logic: collection. updateOne(eq(“flag”, true), new Document(“$set”, new Document(“title”, “Portable Space Ball”))); If the title field does not exist, $set will add a new field with the specified value, provided that the new field does not violate a type constraint.
How do I query a nested field in MongoDB?
Query on Nested Field To specify a query condition on fields in an embedded/nested document, use dot notation ( “field. nestedField” ). When querying using dot notation, the field and nested field must be inside quotation marks.
How do I update a field value in MongoDB?
MongoDB Update() Document with Example
- Step 1) Issue the update command.
- Step 2) Choose the condition which you want to use to decide which document needs to be updated.
- Step 3) Use the set command to modify the Field Name.
- Step 4) Choose which Field Name you want to modify and enter the new value accordingly.
- Output:
How do I add a field to an existing document in MongoDB using a compass?
Procedure
- Click the Add Data dropdown and select Insert Document.
- Select the appropriate view based on how you would like to insert documents. Click the { } brackets for JSON view. This is the default view. Click the list icon for Field-by-Field mode. JSON View Field-by-Field Editor.
What is sub document in MongoDB?
In Mongoose, subdocuments are documents that are nested in other documents. You can spot a subdocument when a schema is nested in another schema. Note: MongoDB calls subdocuments embedded documents. Mongoose helps you create nested schemas when you nest an object in another object.
How do I add an array of documents in MongoDB?
insertMany() can insert multiple documents into a collection. Pass an array of documents to the method. The following example inserts three new documents into the inventory collection. If the documents do not specify an _id field, MongoDB adds the _id field with an ObjectId value to each document.
How do I edit a field in MongoDB?
The MongoDB shell provides the following methods to update documents in a collection:
- To update a single document, use db. collection. updateOne() .
- To update multiple documents, use db. collection. updateMany() .
- To replace a document, use db. collection. replaceOne() .
How do I change the field type in MongoDB?
Change the field type in a single document In this example, we want to change the dob field type from string to date – but only in a single document. Right-click on the field you want to edit (e.g. dob ) and choose Edit Value/Type. Under Type, choose the new field type (e.g. date ).
How to add a sub- document to sub-document array in MongoDB?
How to add a sub-document to sub-document array in MongoDB? Use the $push operator to add a sub-document. Let us first create a collection with documents −
What is the difference between multimulti and updatemany in MongoDB?
Multi: If set to true, updates multiple documents that meet the query criteria. If set to false, updates one document. This is for Mongo versions prior to 2.2. For latest versions the query is changed a bit Since MongoDB version 3.2 you can use updateMany (): To clarify, the syntax is as follows for MongoDB version 4.0.x:
Is MongoDB schema-free?
MongoDB is “schema-free”, but it doesn’t mean you don’t need to think about your schema. Key names should be descriptive, and in your case, f.e. “S2” does not really mean anything. In order to do most kinds of queries and operations, you will need to redesign you schema to store your data like this:
How to add new_field to all the documents in a collection?
In case you want to add a new_field to all your collection, you have to use empty selector, and set multi flag to true (last param) to update all the documents In the above example last 2 fields false, true specifies the upsert and multi flags. Upsert: If set to true, creates a new document when no document matches the query criteria.