How do you write a case statement in SQL?

Where do you put case statements in SQL?

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 do you write two 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.

How do I add a case statement to 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 write CASE statement in where clause?


THIS IS IMPORTANT:  What does cast in SQL do?

We can use a case statement in Where, Order by and Group by clause. … So, by using a CASE statement with the where condition displays the result.

How do you do not in SQL?

Overview. The SQL Server NOT IN operator is used to replace a group of arguments using the <> (or !=) operator that are combined with an AND. It can make code easier to read and understand for SELECT, UPDATE or DELETE SQL commands.

Can you use CASE statements in a join?

A conditional column join is a fancy way to let us join to a single column and to two (or more) columns in a single query. We can accomplish this by using a case statement in the on clause of our join. A case statement allows us to test multiple conditions (like an if/else if/else) to produce a single value.

How do you use multiple values in a case statement?

SQL:2003 standard allows to define multiple values for simple case expression: SELECT CASE c. Number WHEN ‘1121231’,’31242323′ THEN 1 WHEN ‘234523’,’2342423′ THEN 2 END AS Test FROM tblClient c; It is optional feature: Comma-separated predicates in simple CASE expression“ (F263).

Which statement is used in case of multiple conditions?

SQL case statement with multiple conditions is known as the Search case statement. So, You should use its syntax if you want to get the result based upon different conditions -.

How many tables can be join in SQL query?

Theoretically, there is no upper limit on the number of tables that can be joined using a SELECT statement. (One join condition always combines two tables!) However, the Database Engine has an implementation restriction: the maximum number of tables that can be joined in a SELECT statement is 64.

THIS IS IMPORTANT:  What is SQL explain its features?

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.

Can we use CASE statement in update query?

I have SQL server Table in which there is column that I wanted to update according to a 2 columns value that are present in current row. In this scenario, we can use CASE expression. CASE statement works like IF-THEN-ELSE statement. …

Is else mandatory in case statement 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.

Categories BD