Types of Queries in DBMS

What is a Query?

Query is basically use for request to database for get information and data. Normally create a query for get data from data base with certen condition and specific data related to any table.
Basically Use multiple type Query for get data from database. and same like save data , update data and delete data from database.

DBMS Query Types

• Data Definition Language (DDL)
• Data Manipulation Language (DML)
• Data Control Language (DCL)
• Transaction Control Language (TCL)
• Join Queries
• Subqueries
• Recursive Queries
• Analytical Queries
• Search Queries
• NoSQL Queries

Description of Each Query Type with Examples

CREATE TABLE student_detail (id INT, student_name VARCHAR(50), age INT);
ALTER TABLE student_detail ADD address VARCHAR(100);
DROP TABLE student_detail;
        

INSERT INTO student_detail (id, name, age) VALUES (1, 'Alice', 20);
UPDATE student_detail SET age = 21 WHERE id = 1;
DELETE FROM student_detail WHERE id = 1;
SELECT * FROM student_detail;
        

GRANT SELECT, INSERT ON students TO user1;
REVOKE SELECT ON students FROM user1;
        

BEGIN TRANSACTION;
COMMIT;
ROLLBACK;
        

SELECT students.name, courses.course_name
FROM students
INNER JOIN courses ON students.id = courses.student_id;
        

SELECT name FROM students
WHERE age = (SELECT MAX(age) FROM students);
        

WITH RECURSIVE employee_hierarchy AS (
  SELECT employee_id, manager_id FROM employees WHERE manager_id IS NULL
  UNION ALL
  SELECT e.employee_id, e.manager_id
  FROM employees e
  INNER JOIN employee_hierarchy h ON e.manager_id = h.employee_id
)
SELECT * FROM employee_hierarchy;
        

SELECT department, AVG(salary) OVER (PARTITION BY department) AS avg_salary
FROM employees;
        

SELECT * FROM students WHERE name LIKE '%A%';
        

db.students.find({ age: { $gt: 20 } });
        

Flowchart: How a Database Query Works