MongoDB is a cross-platform document-oriented database program and the most popular NoSQL database program. The term NoSQL means non-relational. MongoDB stores the data in the form of key-value pairs. It is an Open Source, Document Database which provides high performance and scalability along with data modeling and data management of huge sets of data in an enterprise application. MongoDB also provides the feature of Auto-Scaling. It uses JSON like documents, which makes the database very flexible and scalable.
Finding data from the collection or the database
In MongoDB, there are 2 functions that are used to find the data from the collection or the database.
In MongoDB, to select data from the collection we use
find_one() method. It returns the first occurred information in the selection and brings backs as an output. In
find_one() method there are no parameters required as it brings the first occurrence of information from the database.
Example 1: Find the first document from the student’s collection/database.
Let’s suppose the database looks like this –
find() method is used to select data from the database. It returns all the occurrences of the information stored in the collection. It has 2 types of parameters, The first parameter of the
find() method is a query object. In the below example we will use an empty Query object, which will select all information from the collection.
Note: It works the same as SELECT* without any parameter.
The second parameter to the find() method is that you can specify the field to include in the result. The second parameter passed in the find() method is of object type describing the field. Thus, this parameter is optional.
If omitted then all the fields from the collection/database will be displayed into the result.
To include the field in the result the value of the parameter passed should be 1, if the value is 0 then it will be excluded from the result.
Example: Return only the names and address, not the id:
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