postgres if else

1-- use postgress case
2
3SELECT name, continent, indep_year,
4    CASE WHEN indep_year < 1900 THEN 'before 1900'
5         WHEN indep_year <= 1930 THEN 'between 1900 and 1930'
6         ELSE 'after 1930' END
7         AS indep_year_group
8FROM countries
9ORDER BY indep_year_group;

1
2        
3            
4        
5     DO $$
6DECLARE
7  a integer := 10;
8  b integer := 20;
9BEGIN 
10  IF a > b THEN
11	RAISE NOTICE 'a is greater than b';
12  END IF;
13
14  IF a < b THEN
15	RAISE NOTICE 'a is less than b';
16  END IF;
17
18  IF a = b THEN
19	RAISE NOTICE 'a is equal to b';
20  END IF;
21END $$;
22

1if condition then
2  statements;
3else
4  alternative-statements;
5END if;