SQL Keyword AS
The AS is used to define an alias name to a table or a column in an SQL statement.
- If the alias name contains spaces, then it must be enclosed with double quotation marks or square brackets.
- The alias name exists only for the duration of the query.
The below SQL uses alias names for the column names.
SELECT customer_id AS id, customer_name AS name
FROM customers;
The below SQL uses alias names for the column names, where the alias names contain spaces that are enclosed with double quotes or square brackets.
SELECT customer_name AS "Customer Name", contact_name AS [Contact Person]
FROM customers;
The below SQL uses alias names for the table names.
SELECT ord.order_id, ord.order_date, cust.customer_name
FROM customers AS cust, orders AS ord
WHERE cust.customer_name ="James Bond"
AND cust.customer_id = ord.customer_id;