What is case statement in SQL Server?
The case statement in SQL returns a value on a specified condition. We can use a Case statement in select queries along with Where, Order By, and Group By clause. It can be used in the Insert statement as well. Similarly, if we change the condition in a Case statement in SQL, it returns appropriate expression.
Can I use CASE statement in where clause?
CASE can be used in any statement or clause that allows a valid expression. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as select_list, IN, WHERE, ORDER BY, and HAVING.
Is null in case statement SQL Server?
Thanks – Adam. NULL does not equal anything. The case statement is basically saying when the value = NULL .. it will never hit.
How does SQL CASE statement work?
The SQL CASE Statement The CASE statement goes through conditions and returns a value when the first condition is met (like an if-then-else statement). So, 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.
Can we write subquery in case statement?
Case Statement and Subquery Example This example use the Subquery inside a Case Statement in SQL Server. First, the Subquery will execute and finds the Average of the Sales amount. Same as IF ELSE statement.
Does SQL CASE statement short circuit?
SQL Server usually does short-circuit evaluation for CASE statements (SQLFiddle): –Does not fail on the divide by zero. SELECT CASE WHEN 1/1 = 1 THEN ‘Case 1’ WHEN 2/0 = 1 THEN ‘Case 2’ END; –Fails on the divide by zero.
Can we use CASE statement without else in SQL?
3 Answers. You can use a WHERE clause to restrict the output. Or if you wanted to showcase some other value instead of null use an else part inside the CASE statement.
Where does CASE statement go in SQL?
The CASE statement always goes in the SELECT clause. CASE must include the following components: WHEN , THEN , and END . ELSE is an optional component.
When to use the SQL CASE statement?
According to MS SQL Docs, a CASE statement can be used throughout the SELECT statement . CASE can be used in any statement or clause that allows a valid expression. For example, you can use CASE in statements such as SELECT, UPDATE, DELETE and SET, and in clauses such as select_list, IN, WHERE, ORDER BY, and HAVING.
How does case statement work in SQL?
The Case statement in SQL is mostly used in a case with equality expressions. The SQL Case statement is usually inside of a Select list to alter the output. What it does is evaluates a list of conditions and returns one of the multiple possible result expressions.
What is proper case in SQL?
Syntax. To view Transact-SQL syntax for SQL Server 2014 and earlier,see Previous versions documentation.
How to use case in SQL?
SQL CASE The SQL CASE statement. The CASE statement is SQL’s way of handling if/then logic. Adding multiple conditions to a CASE statement. A quick review of CASE basics: CASE must include the following components: WHEN, THEN, and END. Using CASE with aggregate functions. Using CASE inside of aggregate functions.