MongoDB Query for boolean field as "not true

You can use the $ne (not equal) operator to query for boolean fields that are "not true". This operator returns documents where the field value is either false or does not exist.

Syntax

db.collectionName.find({
    fieldName: { $ne: true }
});

Sample Data

Let us create a collection with employee documents to demonstrate the query ?

db.queryForBooleanFieldsDemo.insertMany([
    { "EmployeeName": "Larry", "EmployeeAge": 24, "isOldEmployee": true },
    { "EmployeeName": "Mike", "EmployeeAge": 20, "isOldEmployee": false },
    { "EmployeeName": "Sam", "EmployeeAge": 23, "isOldEmployee": false },
    { "EmployeeName": "David", "EmployeeAge": 25, "isOldEmployee": true },
    { "EmployeeName": "Carol", "EmployeeAge": 27, "isOldEmployee": true }
]);

{
    "acknowledged": true,
    "insertedIds": [
        ObjectId("5c8b7f7680f10143d8431e13"),
        ObjectId("5c8b7f8680f10143d8431e14"),
        ObjectId("5c8b7f9380f10143d8431e15"),
        ObjectId("5c8b7fa280f10143d8431e16"),
        ObjectId("5c8b7fae80f10143d8431e17")
    ]
}

Display all documents to verify the data ?

db.queryForBooleanFieldsDemo.find().pretty();

{
    "_id": ObjectId("5c8b7f7680f10143d8431e13"),
    "EmployeeName": "Larry",
    "EmployeeAge": 24,
    "isOldEmployee": true
}
{
    "_id": ObjectId("5c8b7f8680f10143d8431e14"),
    "EmployeeName": "Mike",
    "EmployeeAge": 20,
    "isOldEmployee": false
}
{
    "_id": ObjectId("5c8b7f9380f10143d8431e15"),
    "EmployeeName": "Sam",
    "EmployeeAge": 23,
    "isOldEmployee": false
}
{
    "_id": ObjectId("5c8b7fa280f10143d8431e16"),
    "EmployeeName": "David",
    "EmployeeAge": 25,
    "isOldEmployee": true
}
{
    "_id": ObjectId("5c8b7fae80f10143d8431e17"),
    "EmployeeName": "Carol",
    "EmployeeAge": 27,
    "isOldEmployee": true
}

Example: Query for "Not True" Boolean Field

Find all employees where isOldEmployee is not true ?

db.queryForBooleanFieldsDemo.find({
    isOldEmployee: { $ne: true }
}).pretty();

{
    "_id": ObjectId("5c8b7f8680f10143d8431e14"),
    "EmployeeName": "Mike",
    "EmployeeAge": 20,
    "isOldEmployee": false
}
{
    "_id": ObjectId("5c8b7f9380f10143d8431e15"),
    "EmployeeName": "Sam",
    "EmployeeAge": 23,
    "isOldEmployee": false
}

Key Points

• The $ne operator matches documents where the field value is not equal to the specified value.
• For boolean fields, { $ne: true } returns documents with false values or missing fields.
• Alternative approaches include { fieldName: false } for exact false matches.

Conclusion

Use the $ne operator with true to query boolean fields that are "not true". This approach effectively filters documents where the boolean field is either false or undefined.