š MongoDB Queries ā Quick Reference & Guide for Developers
MongoDB is a NoSQL, document-oriented database. Instead of using tables and rows like relational databases, MongoDB stores data in JSON-like documents (called BSON). Queries in MongoDB are expressed in JavaScript-like syntax.
š§± Basic Document Example
š 1. Basic Find Query
Find one:
š§° 2. Comparison Operators
| Operator | Meaning |
|---|---|
$eq | Equal to |
$ne | Not equal |
$gt | Greater than |
$gte | Greater than or equal |
$lt | Less than |
$lte | Less than or equal |
Ā
āļø 3. Logical Operators
OR
š§© 4. Array Queries
Match exact:
Match if contains:
Match all:
š§ 5. Field Selection (Projection)
1= include0= exclude
š 6. Sorting, Limiting, Skipping
1= ascending-1= descending
āļø 7. Insert Documents
š ļø 8. Update Documents
Update one:
Update many:
ā 9. Delete Documents
š§Ŗ 10. Regex, Null, Exists, Type
Regex:
Null check:
Exists:
Type check:
š§° Aggregation (Intro)
ā Powerful for reporting, grouping, transforming data
š Helpful Tools
š§Ŗ Mongo Playground
š» Compass GUI ā Visual MongoDB tool
ā Summary
| Action | Method |
|---|---|
| Find | find(), findOne() |
| Insert | insertOne(), insertMany() |
| Update | updateOne(), updateMany() |
| Delete | deleteOne(), deleteMany() |
| Advanced Queries | $gt, $lt, $or, $and, $in, $regex |
