sql case statements code example
Example 1: sql case
CASE
WHEN condition1 THEN result1
WHEN condition2 THEN result2
WHEN conditionN THEN resultN
ELSE result
END
SELECT
CASE
WHEN (1+6 = 6) THEN 'A'
WHEN (1+6 = 7) THEN 'B'
WHEN (1+6 = 8) THEN 'C'
ELSE 'D'
END
FROM DUAL;
Example 2: sql case
Change query output depending on conditions.
Example: Returns users and their subscriptions, along with a new column
called activity_levels that makes a judgement based on the number of
subscriptions.
SELECT first_name, surname, subscriptions
CASE WHEN subscriptions > 10 THEN 'Very active'
WHEN Quantity BETWEEN 3 AND 10 THEN 'Active'
ELSE 'Inactive'
END AS activity_levels
FROM users;
Example 3: case when switch in SQL
SELECT
CASE
WHEN
(MAX(BILLID) IS NULL)
THEN 1
ELSE
(MAX(BILLID))
END
as MAXBILLID from DUAL;
Example 4: sql CASE
SELECT column_name,
CASE
WHEN condition THEN 'Result_1'
WHEN condition THEN 'Result_2'
ELSE 'Result_3'
END
FROM table_name;
Example 5: case statement in sql
Case Statement basically
Like IF - THEN - ELSE statement.
The CASE statement goes through conditions
and returns a value when the
first condition is met and
once a condition is true,
it will stop reading and return the result.
If no conditions are true,
it returns the value in the ELSE clause.
If there is no ELSE part and
no conditions are true, it returns NULL.
FOR EXAMPLE =
CASE
WHEN condition1 THEN result1
WHEN condition2 THEN result2
WHEN conditionN THEN resultN
ELSE result
END
SELECT
CASE
WHEN (1+6 = 6) THEN 'A'
WHEN (1+6 = 7) THEN 'B'
WHEN (1+6 = 8) THEN 'C'
ELSE 'D'
END
FROM DUAL;
Result would be 'B' since it is the first
correct answer