Data Retrieval with SELECT

Basic SELECT Syntax

SELECT column1, column2, ...
FROM table_name;

Select All Columns

SELECT * FROM employees;

Select Specific Columns

SELECT first_name, last_name, salary FROM employees;

Column Aliases

SELECT first_name AS fname,
     last_name AS lname,
     salary * 12 AS annual_salary
FROM employees;

DISTINCT

SELECT DISTINCT department FROM employees;

Calculated Fields

SELECT first_name,
     last_name,
     salary,
     salary * 0.1 AS bonus
FROM employees;

String Concatenation

SELECT CONCAT(first_name, ' ', last_name) AS full_name
FROM employees;

Conditional Selection

SELECT first_name,
     CASE
       WHEN salary > 70000 THEN 'Senior'
       ELSE 'Junior'
     END AS level
FROM employees;