Introduction to SQL 

 SQL kya hai?

SQL (Structured Query Language) ek standard language hai jo aapko database se baat karne mein help karti hai. Iska use hum database ke andar:

• Data insert karne 

• Data retrieve (nikalne) 

• Data update (badalne) 

• Data delete (hatane) 

mein karte hain.

Simple shabdon mein: SQL ek language hai jo database se kaam karne ke liye use hoti hai.

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 SQL ka use kyun hota hai?

Har company, college ya organization ke paas bahut saari data hoti hai — jaise student records, employee data, etc.
In data ko manage karne ke liye SQL ka use hota hai.

SQL se hum:

• Naya data dalte hain (INSERT)

• Purana data dekhte hain (SELECT)

• Data update karte hain (UPDATE)

• Data delete karte hain (DELETE)

 Basic SQL Commands

Maan lo humare paas ek Student naam ka table hai:

1. SELECT – Data dekhne ke liye

 Output: Saare students ka data show karega.

2. INSERT – Naya student add karne ke liye

3. UPDATE – Kisi ka age change karne ke liye

4. DELETE – Data delete karne ke liye

 SQL Commands ke Types

SQL commands 5 categories mein divide hoti hain:

 DDL ka Example:

 Ye command ek naya table banata hai jiska naam Student hai.

 SQL ke Benefits (Fayde)

1. Asaan – Syntax simple hota hai.

2. Standard Language – Har RDBMS (MySQL, Oracle) mein use hota hai.

3. Powerful – Badi databases ko easily handle karta hai.

4. Flexible – Alag-alag types ke data ke saath kaam karta hai.

5. Secure – Access control aur permission de sakta hai.

 Real-Life Example:

Aapke college mein ek database hai jisme students ka data store hai.

• 18 se upar ke students dekhne ke liye:

• Naya student add karne ke liye:

• Graduate ho chuke students delete karne ke liye:

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 Summary Table