MongoDB
MongoDB: How to Check if Field Exists
You can use the following methods to check if a field exists in a collection in MongoDB:
Method 1: Check if Field Exists
db.myCollection.find({ "myField": {...
MongoDB
MongoDB: How to List All Field Names
You can use the following syntax to list all field names in a collection in MongoDB:
Object.keys(db.myCollection.findOne())
This particular example lists every field name in a...
MongoDB
MongoDB: How to Use the OR ($or) Operator in Queries
You can use the $or operator in MongoDB to query for documents that meet one of multiple criteria.
This operator uses the following basic syntax:
db.myCollection.find({
...
MongoDB
MongoDB: How to Use the AND ($and) Operator in Queries
You can use the $and operator in MongoDB to query for documents that meet multiple criteria.
This operator uses the following basic syntax:
db.myCollection.find({
"$and":...
MongoDB
How to Rename Fields in MongoDB (3 Examples)
You can use the following methods to rename fields in MongoDB:
Method 1: Rename One Field
db.collection.updateMany({}, {$rename:{"oldField":"newField"}}, false, true)
Method 2: Rename Multiple Fields
db.collection.updateMany({}, {$rename:{"old1":"new1", "old2":"new2"}},...
MongoDB
MongoDB: How to Find Length of String
You can use the following methods to find the length of a string in MongoDB and use this string length in queries:
Method 1: Find...
Aggregation in MongoDB
MongoDB: How to Calculate the Average Value of a Field
You can use the following methods to calculate the average value of a field in MongoDB:
Method 1: Calculate Average of Field
db.collection.aggregate()
Method 2: Calculate Average...
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