SQL (Structured Query Language) ek programming language hai, jo relational database management systems (RDBMS) ke liye data management aur data manipulation ke liye istemal hoti hai. SQL ka istemal database se data retrieve, modify, update, aur manage karne ke liye hota hai.
SQL ke kuch mukhya karya hain:
1. Data Retrieval (Data Prapti): SQL ka upayog data retrieve karne ke liye hota hai. Aap SQL queries ka istemal karke database se specific data records ya entries ko select kar sakte hain. Isme SELECT statement ka upayog hota hai.
2. Data Manipulation (Data Parivartan): SQL se aap database me data ko insert, update, aur delete kar sakte hain. Iske liye INSERT, UPDATE, aur DELETE statements ka upayog hota hai.
3. Data Definition (Data Vivaran): SQL ki madhyam se aap database schema ko define kar sakte hain, jisme tables, relationships, indexes, aur constraints shamil hote hain. Isme CREATE, ALTER, aur DROP statements ka upayog hota hai.
4. Data Control (Data Niyantran): SQL se aap database access aur security control kar sakte hain. Aap permissions, roles, aur user access ko configure kar sakte hain.
SQL ka ek udaharan dekhte hain. Agar aap ek simple database me ek table "Employees" jiska naam hai, us table me karmachariyon ke data ko store kar rahe hain, to aap SQL ka istemal kisi particular karmachari ke janm din janne ke liye kar sakte hain: kuch is tarah se
SELECT FirstName, LastName, DateOfBirth
FROM Employees
WHERE EmployeeID = 101;
Is SQL query se "Employees" table se EmployeeID 101 ke liye karmachari ke naam, Last name, aur janm din prapt kiya ja sakta hai.
SQL ek powerful aur standard language hai, jo relational databases jaise MySQL, PostgreSQL, SQL Server, Oracle, aur SQLite ke sath istemal hota hai. Developers, database administrators, aur data analysts SQL ka istemal karte hain database management, data retrieval, aur data manipulation ke liye.
