Add MD5 hash value to MongoDB collection?

To add MD5 hash values to a MongoDB collection, use the hex_md5() function combined with forEach() to iterate through documents and generate hash values for specific fields like passwords.

Syntax

db.collection.find().forEach(function(doc) {
    doc.hashField = hex_md5(doc.sourceField);
    db.collection.save(doc);
});

Sample Data

db.addMd5HashValueDemo.insertMany([
    {"UserName": "Adam", "UserPassword": "Adam123456"},
    {"UserName": "Chris", "UserPassword": "Chris_121#"}
]);

{
    "acknowledged": true,
    "insertedIds": [
        ObjectId("5cd6a4c66d78f205348bc619"),
        ObjectId("5cd6a4e46d78f205348bc61a")
    ]
}

Display the original documents ?

db.addMd5HashValueDemo.find();

{ "_id": ObjectId("5cd6a4c66d78f205348bc619"), "UserName": "Adam", "UserPassword": "Adam123456" }
{ "_id": ObjectId("5cd6a4e46d78f205348bc61a"), "UserName": "Chris", "UserPassword": "Chris_121#" }

Add MD5 Hash Values

Generate MD5 hash for each user's password and store it in a new field ?

db.addMd5HashValueDemo.find().forEach(function(documentPass) {
    documentPass.Value = hex_md5(documentPass.UserPassword);
    db.addMd5HashValueDemo.save(documentPass);
});

Verify Results

db.addMd5HashValueDemo.find();

{ "_id": ObjectId("5cd6a4c66d78f205348bc619"), "UserName": "Adam", "UserPassword": "Adam123456", "Value": "6523857c2bf79b63fd5fa0322575f7be" }
{ "_id": ObjectId("5cd6a4e46d78f205348bc61a"), "UserName": "Chris", "UserPassword": "Chris_121#", "Value": "3391ccbe33624258cafa23aa50301615" }

Key Points

• The hex_md5() function generates a 32-character hexadecimal MD5 hash.
• Use forEach() to process multiple documents in batch operations.
• The hash is stored as a new field while preserving the original password field.

Conclusion

MongoDB's hex_md5() function enables easy generation of MD5 hashes for any string field. Combine it with forEach() to add hash values to existing collections efficiently.