and in if in sql code example

Example 1: if in sql

-- PL/SQL
BEGIN
    IF my_val = 1 THEN [...]
    ELSE [...]
    END IF;
END;
-- In a query (DUAL is for Oracle)
SELECT CASE WHEN my_col = 1 THEN 'Ok' ELSE 'Ko' END AS my_result
FROM DUAL;

Example 2: in condition in sql

IN condition allows you to easily test
if an expression matches any value
in a list of values.
It is for reducing  multiple OR
conditions in a SELECT, INSERT, 
UPDATE, or DELETE statement.