Filter column interval year to month - oracle

Question

i have column it`s look like that https://i.stack.imgur.com/j7Nwh.png it is format +Year-Month an i need to extract some information for example:
If the period is 0 return "No Warranty"
if the period is more than 0 return number year number months ...
any suggestion how to approach, I know I have to use some Case or IF Else structure

Answer 1

Use a CASE expression:
SELECT warranty_period,
CASE warranty_period
WHEN INTERVAL '0-0' YEAR TO MONTH
THEN 'No warranty'
ELSE TO_CHAR(warranty_period)
END AS descr
FROM table_name
Which, for the sample data:
CREATE TABLE table_name (warranty_period) AS
SELECT INTERVAL '0-0' YEAR TO MONTH FROM DUAL UNION ALL
SELECT INTERVAL '0-1' YEAR TO MONTH FROM DUAL UNION ALL
SELECT INTERVAL '1-0' YEAR TO MONTH FROM DUAL UNION ALL
SELECT INTERVAL '1-2' YEAR TO MONTH FROM DUAL;
Outputs:
WARRANTY_PERIOD
DESCR
+00-00
No warranty
+00-01
+00-01
+01-00
+01-00
+01-02
+01-02
Or, if you want a different format then EXTRACT the component parts:
SELECT warranty_period,
CASE warranty_period
WHEN INTERVAL '0-0' YEAR TO MONTH
THEN 'No warranty'
ELSE EXTRACT(YEAR FROM warranty_period) || 'y ' || EXTRACT(MONTH FROM warranty_period) || 'm'
END AS descr
FROM table_name
Which outputs:
WARRANTY_PERIOD
DESCR
+00-00
No warranty
+00-01
0y 1m
+01-00
1y 0m
+01-02
1y 2m
or:
SELECT warranty_period,
CASE
WHEN warranty_period <= INTERVAL '0-0' YEAR TO MONTH
THEN 'No warranty'
WHEN warranty_period < INTERVAL '1-0' YEAR TO MONTH
THEN EXTRACT(MONTH FROM warranty_period) || ' months'
WHEN EXTRACT(MONTH FROM warranty_period) = 0
THEN EXTRACT(YEAR FROM warranty_period) || ' years'
ELSE EXTRACT(YEAR FROM warranty_period) || ' years and ' || EXTRACT(MONTH FROM warranty_period) || ' months'
END AS descr
FROM table_name
Outputs:
WARRANTY_PERIOD
DESCR
+00-00
No warranty
+00-01
1 months
+01-00
1 years
+01-02
1 years and 2 months
fiddle