Skill Topic · Cinematic

📘 SQL PRIMARY KEY - Table Ka Main Identifier

PRIMARY KEY table ka sabse important column hai — har row ko uniquely identify karta hai, NULL aur…

Overview

📘 SQL PRIMARY KEY - Table Ka Main Identifier — Quick Facts

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Practice: Recommendation

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Type: INT ya BIGINT (surrogate key)

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Auto Increment: Hamesha use karo

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Naming: pk_tablename convention follow karo

Topic 1

📌 PRIMARY KEY Kya Hai?

🤖 PRIMARY KEY = NOT NULL + UNIQUE combined. Yeh table ka main identifier hai — har row ko…

Topic 2

📌 PRIMARY KEY in CREATE TABLE

🧠 Single Column: `sql -- Column level: CREATE TABLE Customers ( CustomerID INT NOT NULL…

Topic 3

📌 Composite PRIMARY KEY (Multiple Columns)

💡 Jab ek column unique nahi ho sakta, to multiple columns ka combination PRIMARY KEY banta…

Topic 4

📌 ALTER TABLE se PRIMARY KEY Add

⚡ `sql -- Single column: ALTER TABLE Customers ADD PRIMARY KEY (CustomerID); -- Named:…

Topic 5

📌 PRIMARY KEY Drop Karna

🎯 `sql -- MySQL: ALTER TABLE Customers DROP PRIMARY KEY; -- SQL Server: ALTER TABLE…

Topic 6

📌 PRIMARY KEY Types — Natural vs Surrogate

🔮 ` Natural vs Surrogate Key: ┌──────────────────────────────────────────────────┐ │ │ │…

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📌 PRIMARY KEY + FOREIGN KEY Relationship

🌐 `sql -- Parent table (PRIMARY KEY) CREATE TABLE Customers ( CustomerID INT PRIMARY KEY,…

Topic 8

📌 PRIMARY KEY Best Practices

📊 | Practice | Recommendation | |----------|---------------| | Type | INT ya BIGINT…

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📌 Complete Example

🤖 `sql -- Database with proper PRIMARY KEYs: CREATE TABLE Departments ( DeptID INT NOT NULL…

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✅ Summary

🧠 KEY POINTS: - PRIMARY KEY = NOT NULL + UNIQUE — table ka main identifier - Ek table me…

Quick Quiz

Quiz — Question 1

📘 SQL PRIMARY KEY - Table Ka Main Identifier ka sabse sahi definition kya hai?

Quick Quiz

Quiz — Question 2

📘 SQL PRIMARY KEY - Table Ka Main Identifier ka 'Type' kya hai?

Complete! 🎉

📘 SQL PRIMARY KEY - Table Ka Main Identifier Complete!

Aliens School · HIEN · Cinematic Knowledge

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