Case

CASE is used to provide if-then-else type of logic to SQL. Its syntax is:

SELECT CASE ("column_name")
WHEN "condition1" THEN "result1"
WHEN "condition2" THEN "result2"
...
[ELSE "resultN"]
END
FROM "table_name"

“condition” can be a static value or an expression. The ELSE clause is optional.

In our Table Store_Information example,

Table Store_Information

if we want to multiply the sales amount from ‘Los Angeles’ by 2 and the sales amount from ‘San Diego’ by 1.5, we key in,

SELECT store_name, CASE store_name
WHEN 'Los Angeles' THEN Sales * 2
WHEN 'San Diego' THEN Sales * 1.5
ELSE Sales
END
"New Sales",
Date
FROM Store_Information

“New Sales” is the name given to the column with the CASE statement.

Result: