DQL (Data Query Language)

DQL (Data Query Language) forms the core of data retrieval. DQL commands, specifically the SELECT statement, allows to extract and manipulate data from the database tables based on specific criteria.

SELECT

Retrieves data from one or more tables based on a set of conditions.

• Syntax

SELECT [SELECT_list]
FROM [schema_name.]table_name [, ...]
WHERE condition
[GROUP BY column_list]
[HAVING condition]
[ORDER BY column_list ASC|DESC]

• Example

SELECT ProductID, COUNT(*) AS Total_Orders
FROM OrderItems
GROUP BY ProductID
HAVING COUNT(*) > 5;