Pattern matching in MongoDB with regex
In this post, you will learn how to match mongodb documents with a partial value. This is similar to pattern matching using LIKE predicate in SQL.
Finding a document in MongoDB using partial value of a field can be done using a Regular Expression instead of a string value.
The users collection has the following data.
db.users.find({})
{
"_id": ObjectId("5e16e8a3c3775d62f3acbe72"),
"name": "Kemba Walker",
"username": "kwalk",
"role": "Staff",
"group": ["Staff"]
}
{
"_id": ObjectId("5e203b5c5981cd83c5ae1398"),
"name": "John Rashford",
"username": "jrash",
"team": "Manager",
"group": ["Managers"]
}
{
"_id": ObjectId("5e5e01cb3ef4456a4f739f62"),
"name": "Jim Whitaker",
"username": "jwhit",
"role": "Admin",
"group": ["Admin"]
}Let’s say I want to find the users whose name starts with J.
db.users.find({name: /J/})
{
"_id": ObjectId("5e203b5c5981cd83c5ae1398"),
"name": "John Rashford",
"username": "jrash",
"team": "Manager",
"group": ["Managers"]
}
{
"_id": ObjectId("5e5e01cb3ef4456a4f739f62"),
"name": "Jim Whitaker",
"username": "jwhit",
"role": "Admin",
"group": ["Admin"]
}If you want this find filter be case insensitve, just add i after the /
db.users.find({name: /J/i})This will filter the users whose name starts with lowercase J (j) too.
