GET operation retrieves data from a table.
Basic Syntax
Get All Records
| Database | Output |
|---|---|
| PostgreSQL | SELECT * FROM users |
| MySQL | SELECT * FROM users |
| MongoDB | db.users.find({}) |
Select Specific Columns
| Database | Output |
|---|---|
| PostgreSQL | SELECT id, name, email FROM users |
| MySQL | SELECT id, name, email FROM users |
| MongoDB | db.users.find({}, { id: 1, name: 1, email: 1 }) |
Simple WHERE Clause
| Database | Output |
|---|---|
| PostgreSQL | SELECT * FROM users WHERE id = 1 |
| MySQL | SELECT * FROM users WHERE id = 1 |
| MongoDB | db.users.find({ id: 1 }) |
Multiple Conditions
| Database | Output |
|---|---|
| PostgreSQL | SELECT * FROM users WHERE age > 21 AND status = 'active' |
| MongoDB | db.users.find({ age: { $gt: 21 }, status: 'active' }) |
Combine Columns and Conditions
| Database | Output |
|---|---|
| PostgreSQL | SELECT id, name FROM users WHERE active = true |
| MongoDB | db.users.find({ active: true }, { id: 1, name: 1 }) |
Limit Results
| Database | Output |
|---|---|
| PostgreSQL | SELECT * FROM users LIMIT 10 |
| MySQL | SELECT * FROM users LIMIT 10 |
| MongoDB | db.users.find({}).limit(10) |
Skip Results (Pagination)
| Database | Output |
|---|---|
| PostgreSQL | SELECT * FROM users LIMIT 10 OFFSET 20 |
| MongoDB | db.users.find({}).skip(20).limit(10) |
Standalone Aggregates
Aggregates can also be used as standalone operations:| Database | Output |
|---|---|
| PostgreSQL | SELECT COUNT(*) FROM users |
| PostgreSQL | SELECT SUM(amount) FROM orders WHERE status = 'completed' |