What is the use of CASE statement in SQL?

What is the use of CASE statement in SQL?

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.

How do you declare a case in SQL?

5 Answers. In SQL Server I would write it like this: DECLARE @Test int; DECLARE @Result char(10); SET @Test = 10; SET @Result = CASE @Test WHEN 10 THEN ‘OK test’ END Print @Result; The WHEN clause does not have @Test = 10 , as the @Test variable is stated in the CASE clause.

How do you do if then in SQL?

Syntax. IF (a <= 20) THEN c:= c+1; END IF; If the Boolean expression condition evaluates to true, then the block of code inside the if statement will be executed. If the Boolean expression evaluates to false, then the first set of code after the end of the if statement (after the closing end if) will be executed.

Can we use select in case?

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 case expressions in SQL are?

SQL CASE Introduction to SQL CASE expression. The SQL CASE expression allows you to evaluate a list of conditions and returns one of the possible results. Simple CASE expression. CASE expression WHEN when_expression_1 THEN result_1 WHEN when_expression_2 THEN result_2 WHEN when_expression_3 THEN result_3 Searched CASE expression.

What is Case Logic in SQL?

SQL CASE is a very unique conditional statement providing if/then/else logic for any ordinary SQL command, such as SELECT or UPDATE. It then provides when-then-else functionality (WHEN this condition is met THEN do_this).

What is a case when statement in SQL?

CASE is the special scalar expression or conditional statement in the SQL language which returns a single value based on the evaluation of a statement. It can be used in Select, Where and Order By clause. A Case expression is mostly used in SQL stored procedures or as a formula for a particular column, which optimizes the SQL statements.