Chapter:-3 (Hindi)
4. Relational Algebra
Relational Algebra
Relational Algebra एक procedural query language है जो relations पर operations apply करके नई relations generate करती है।
यह SQL की mathematical foundation है।
🔹 Basic Relational Algebra Operations
|
Operation |
Symbol |
अर्थ |
|
Selection |
σ |
Rows select करना |
|
Projection |
π |
Columns select करना |
|
Union |
∪ |
Tuples combine करना |
|
Set Difference |
− |
Common हटाना |
|
Cartesian Product |
× |
All combinations |
|
Rename |
ρ |
Name बदलना |
|
Join |
⨝ |
Related data combine करना |