Category: SQL Tutorial

SQL COUNT function

Here’s a clean and practical guide to the SQL COUNT function, including behavior with NULLs, best practices, and real-world examples. What SQL COUNT function Does COUNT() returns the number of rows that match a...

SQL Tutorial

SQL MIN and MAX Functions

Here is a clear and practical guide to the SQL MIN and MAX Functions, including examples, behavior notes, and best practices. What SQL MIN and MAX Functions Do MIN() returns the smallest value in...

SQL Tutorial

SQL Aggregate Functions

Here’s a clear, complete guide to SQL Aggregate Functions — what they do, how they behave with NULLs, and best-practice examples. What Are SQL Aggregate Functions? Aggregate functions take multiple rows and return a single...

SQL Tutorial

SQL SELECT TOP Clause

SQL SELECT TOP Clause Here’s a clear and practical guide to the SQL SELECT TOP Clause, including differences across database engines. Basic Usage (SQL Server / MS Access)

SELECT TOP 10 *
FROM employees;

1 2	SELECT TOP 10 * FROM employees;

This returns the first 10...

SQL Tutorial

SQL DELETE Statement

SQL DELETE Statement (Beginner → Advanced) The DELETE statement in SQL is used to remove one or more rows (records) from a table.It is a DML (Data Manipulation Language) command and is very important...

SQL Tutorial

SQL UPDATE

SQL UPDATE Here is a clear and practical guide to the SQL UPDATE statement`, with best-practice examples you can use immediately. Basic Syntax (ANSI SQL)

UPDATE table_name
SET column1 = value1,
column2 = value2
WHERE condition;

UPDATE table_name

SET column1 = value1,

column2 = value2

WHERE condition;

Always include a WHERE clause unless you intend...

SQL Tutorial

SELECT column1, column2, ...
FROM table_name
WHERE NOT condition;

SELECT column1, column2, ...

FROM table_name

WHERE NOT condition;

2. Example:...

SQL Tutorial

SQL OR Operator

SQL OR Operator In SQL OR Operator is used inside the WHERE clause to combine conditions.A row is returned if at least one of the conditions is TRUE. 1. Basic Syntax

SELECT column1, column2, ...
FROM table_name
WHERE condition1 OR condition2;

SELECT column1, column2, ...

FROM table_name

WHERE condition1 OR condition2;

2. Example:...

Category: SQL Tutorial

SQL COUNT function

SQL MIN and MAX Functions

SQL Aggregate Functions

SQL SELECT TOP Clause

SQL DELETE Statement

SQL UPDATE

SQL NULL values

SQL INSERT INTO

SQL NOT Operator

SQL OR Operator