Some of the most important SQL commands.

SQL, Structured Query Language, is a programming language designed to manage data stored in relational databases. SQL operates through simple, declarative statements. This keeps data accurate and secure, and it helps maintain the integrity of databases, regardless of size.

Most of the actions you need to perform on a database are done with SQL statements.


  • Data Definition Language (DDL)
  • Data Manipulation Language (DML)
  • Transaction Control Language (TCL)
  • Data Control Language (DCL)



SELECT column_name 
FROM table_name;

SELECT statements are used to fetch data from a database (
extracts data from a database ). Every query will begin with SELECT.


ALTER TABLE table_name 
ADD column_name datatype;

ALTER TABLE lets you add columns to a table in a database.
Modifies a table.


SELECT column_name,
    WHEN condition THEN 'Result_1'
    WHEN condition THEN 'Result_2'
    ELSE 'Result_3'
FROM table_name;

CASE statements are used to create different outputs (usually in the SELECT statement). It is SQL’s way of handling if-then logic.


CREATE TABLE table_name (
  column_1 datatype, 
  column_2 datatype, 
  column_3 datatype

CREATE TABLE creates a new table in the database. It allows you to specify the name of the table and the name of each column in the table.

We have an entire article on creating tables in MySQL.


INSERT INTO table_name (column_1, column_2, column_3) 
VALUES (value_1, 'value_2', value_3);

INSERT statements are used to add a new row to a table.


SELECT column_name(s)
FROM table_name
WHERE column_name operator value;

WHERE is a clause that filters the result set to include only rows where the specified condition is true.


UPDATE table_name
SET some_column = some_value
WHERE some_column = some_value;

UPDATE statements allow you to edit rows in a table.


SELECT column_name(s)
FROM table_name
WHERE column_1 = value_1
  AND column_2 = value_2;



SELECT column_name
FROM table_name
WHERE column_name = value_1
   OR column_name = value_2;

OR is an operator that filters the result set to only include rows where either condition is true.

These were the most common and basic SQL commands. There are many more commands in SQL.

Thank You.