Data Models in DBMS – Simple Hinglish Mein

 Data Model kya hota hai?

Simple shabdon mein:

Data Model ek blueprint (naksha) hota hai jo batata hai ki data database ke andar kaise store, organize aur access kiya jayega.

Isse humko pata chalta hai:

• Kya information store hogi (jaise Student ka naam, Roll No, Marks)

• Data kaise connect hai (jaise Student multiple Exams deta hai)

• Data ko kaise arrange kiya jayega database ke andar

 Example:

Agar aapko ek college database banana hai:

• Entities: Student, Course, Teacher

• Attributes: Student Name, Roll No, Course Name, Teacher Name

• Relationships: Students Courses ko enroll karte hain, Teachers Courses padhate hain.

Data Model help karta hai is sabko ache se design karne mein.

 Types of Data Models in DBMS

Data Models ke mainly 4 types hote hain:

Ab sabko simple language mein samjhte hain. 

 Hierarchical Model

• Data ko ek tree structure mein organize kiya jata hai. 

• One parent → many children, but ek child ka sirf ek hi parent hota hai.

 Diagram:

• College parent hai.

• Students aur Teachers uske children hain.

 Example:

• University → Colleges → Departments → Students

Important Point: Sirf one-to-many relationship support hota hai.

 Network Model

• Hierarchical jaisa hi hai, but zyada flexible.

• Yahan ek child ke multiple parents ho sakte hain.

• Support karta hai many-to-many relationships.

 Diagram:

 Example:

• Student ek ya zyada Courses me enroll ho sakta hai.

• Course ko multiple Students padh sakte hain.

 Relational Model

• Sabse popular model aaj ke time mein (MySQL, Oracle, etc. use karte hain).

• Data ko tables (rows aur columns) mein store kiya jata hai.

 Table Example:

• Har row ek record hai (ek student ka data).

• Har column ek attribute hai (Name, Course etc.).

Tables ke beech keys (Primary Key, Foreign Key) ke through relations banate hain.

 Entity-Relationship (ER) Model

• Ye model entities aur relationships ko represent karta hai diagram ke form mein.

• Mostly database design karne ke liye use hota hai.

 ER Diagram Example:

• Student aur Course entities hain.

• “Enrolls in” relationship hai.

Entities ke attributes bhi hote hain:

• Student → Student_ID, Name, Age

• Course → Course_ID, Course_Name

Ye model database ko visually design karne mein help karta hai.

 Summary: Short Overview

 Real-Life Example ka Summary

Agar aap ek College Management System banate ho:

• Hierarchical Model: College → Departments → Students

• Network Model: Students multiple Courses mein enroll, aur Courses multiple Students ko padhate hain.

• Relational Model: Students, Teachers, Courses sabko alag tables mein store karke relations banate hain.

• ER Model: Pehle ek diagram banate hain, jisme entities aur unke relations dikhte hain.

 Quick Tip for Students

• Aaj ke zamane mein, Relational Model sabse jyada use hota hai (jaise MySQL, PostgreSQL, SQL Server).

• Database design karte waqt ER Model pehle banate hain, fir usko tables mein convert karte hain.