if x.boy is not null then x.boy else if x.girl is not null then x.girl else if x.dog is not null then x.dog else x.cat THEN DOD If youre just using standard SQL in your application or database, then you can use the CASE statement. CASE can be used in any statement or clause that allows a valid expression. It is also possible to use it with SET, IN, HAVING, ORDER BY and WHERE. Specifies any expression that evaluates to a result type boolean. Acidity of alcohols and basicity of amines. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. So, how can you have an SQL IF statement? Glad it helps! Want to see guides like this for all other Oracle functions? What video game is Charlie playing in Poker Face S01E07? hi Ben WHEN MILITARY_STATUSES (AAIR,DODAF,FAMAF,RAIR,VAIR) Ill demonstrate this using more examples later in this article. If no conditions are true, it will return the value in the ELSE clause. It offers multiple hands-on interactive SQL courses with exercises to cover nested SELECT statements and other challenging SQL features. Bulk update symbol size units from mm to map units in rule-based symbology. In SQL, IF statements in SELECT statements can be done with either of these methods. This process of comparing Case_Expression with Value will continue until Case_Expression finds matching equivalent value from the set of Value_1, Value_2,. Is it possible to use the same CASE statement for both the SELECT clause and the WHERE clause? Notice how the expression (in this case the country field) comes right after the CASE keyword. The CASE statementallows you to perform an IF-THEN-ELSE check within an SQL statement. Syntax CASE [ expression ] { WHEN boolean_expression THEN then_expression } [ . ] select ename, job, sal, case -- Outer Case when ename like 'A%' then case when sal >= 1500 then 'A' -- Nested Case end when ename like 'J%' then case when sal >= 2900 then 'J' -- Nested Case end end as "Name-Grade" From Emp As we need a table object in the outer query, we need to make an alias of the inner query.