Can we use case in select 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. In this article, we would explore the CASE statement and its various use cases.

Can you have a CASE statement in a WHERE clause in SQL?

CASE STATEMENT IN WHERE CLAUSE: The CASE statement returns the value based on condition. We can use a case statement in Where, Order by and Group by clause.

Can you use a subquery in a CASE statement?

Subquery Example The following query example uses the Subquery inside a Case Statement in SQL Server. First, the Subquery will execute and finds the Average of the Sales amount.

How do you execute a CASE statement in SQL?

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.

How do you use a case statement in a SELECT clause?

The CASE statement always goes in the SELECT clause. CASE must include the following components: WHEN , THEN , and END . ELSE is an optional component. You can make any conditional statement using any conditional operator (like WHERE ) between WHEN and THEN .

Can we use case statement in where clause in Oracle?

Introduction to Oracle CASE expression You can use a CASE expression in any statement or clause that accepts a valid expression. For example, you can use the CASE expression in statements such as SELECT , UPDATE , or DELETE , and in clauses like SELECT , WHERE , HAVING , and ORDDER BY .

How do you write multiple conditions in a case statement in SQL?

Here are 3 different ways to apply a case statement using SQL:

  1. (1) For a single condition: CASE WHEN condition_1 THEN result_1 ELSE result_2 END AS new_field_name.
  2. (2) For multiple conditions using AND: CASE WHEN condition_1 AND condition_2 THEN result_1 ELSE result_2 END AS new_field_name.

Can we use case in WHERE clause Oracle?

You can use a CASE expression in any statement or clause that accepts a valid expression. For example, you can use the CASE expression in statements such as SELECT , UPDATE , or DELETE , and in clauses like SELECT , WHERE , HAVING , and ORDDER BY .

How is case statement executed?

CASE Statement. The CASE statement selects a sequence of statements to execute. To select the sequence, the CASE statement uses a selector (an expression whose value is used to select one of several alternatives) or, in the searched CASE statement, multiple search conditions.

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