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How does the case statement work in SQL?

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.

HOW DO CASE statements work?

The CASE statement chooses from a sequence of conditions, and executes a corresponding statement. The CASE statement evaluates a single expression and compares it against several potential values, or evaluates multiple Boolean expressions and chooses the first one that is TRUE .

Where do you put case statements in SQL?

The CASE statement returns the value based on condition. We can use a case statement in Where, Order by and Group by clause. In the Customer table, I have displayed the First Name is Ram or the Last Name is Sharma’s salary. So, by using a CASE statement with the where condition displays the result.

How can use multiple conditions in 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.

Is null in case statement SQL?

Thanks – Adam. NULL does not equal anything. The case statement is basically saying when the value = NULL .. it will never hit.

Is null in case statement SQL Server?

Is else mandatory in case statement 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.

How many case statements are there in SQL?

SQL Server allows for only 10 levels of nesting in CASE expressions. The CASE expression cannot be used to control the flow of execution of Transact-SQL statements, statement blocks, user-defined functions, and stored procedures.

What is SQL Profiler?

Microsoft SQL Server Profiler is a graphical user interface to SQL Trace for monitoring an instance of the Database Engine or Analysis Services. You can capture and save data about each event to a file or table to analyze later.

Can we write case statement without else?

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.

How does case statement work in SQL?

How to Work With Case Statement in Transact-SQL. Case statement execute a sequence of statement depending upon condition. CASE statement in T SQL operates by comparing the first expression to the expression in each WHEN clause for equivalency. Expressions which are equivalent in Case Statement, expression in the THEN clause will be executed.

What does case mean in SQL?

SQL CASE. CASE is used to provide if-then-else type of logic to SQL. There are two formats: The first is a Simple CASE expression, where we compare an expression to static values. The second is a Searched CASE expression, where we compare an expression to one or more logical conditions.

How to use case statement in SQL Server?

Create a Table in SQL Server If you haven’t already done so,create a table in SQL Server.

Define the Rules Next,define the rules for the case statement.

Apply the Case Statement in SQL Server

What is alternative to case statement in SQL Server?

Instead of using a ‘CASE WHEN’ statement , you simply examine your parameter in your WHERE clause, and depending on parameter value, you follow the evaluation with the ‘AND’ operand and the fully qualified filtered statement that includes the database column, the operator, and the value to compare.