Flash cards
Review the key moves
What is the main idea behind Node.js MongoDB Drop?
Lesson checks
Practice each idea before moving on
Short Mimo-style checks built from this lesson's code, terms, and sequence.
Which statement best captures the main point of this lesson?
Complete the missing token from the example code.
___ MongoClient = require('mongodb').MongoClient;Put the learning moves in the order that makes the concept easiest to apply.
Drop Collection
You can delete a table, or collection as it is called in MongoDB, by using the drop() method.
The drop() method takes a callback function containing the error object and the result parameter which returns true if the collection was dropped successfully, otherwise it returns false.
Example
Delete the "customers" table:
let MongoClient = require('mongodb').MongoClient;
let url = "mongodb://localhost:27017/";
MongoClient.connect(url, function(err, db) {
if (err) throw err;
let dbo = db.db("mydb");
dbo.collection("customers").drop(function(err, delOK) {
if (err) throw err;
if (delOK) console.log("Collection deleted");
db.close();
});
});Save the code above in a file called "demo_drop.js" and run the file:
Run "demo_drop.js"
C:\Users\
Your Name
>node demo_drop.jsWhich will give you this result
Collection deleteddb.dropCollection
You can also use the dropCollection() method to delete a table (collection).
The dropCollection() method takes two parameters: the name of the collection and a callback function.
Example
Delete the "customers" collection, using dropCollection():
let MongoClient = require('mongodb').MongoClient;
let url = "mongodb://localhost:27017/";
MongoClient.connect(url, function(err, db) {
if (err) throw err;
let dbo = db.db("mydb");
dbo.dropCollection("customers", function(err, delOK) {
if (err) throw err;
if (delOK) console.log("Collection deleted");
db.close();
});
});Save the code above in a file called "demo_dropcollection.js" and run the file:
Run "demo_dropcollection.js"
C:\Users\
Your Name
>node demo_dropcollection.jsWhich will give you this result
Collection deleted