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. To view Transact-SQL syntax for SQL Server 2014 and earlier, see Previous versions documentation.
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How to write case statements in SQL?
Steps to Apply Case Statements using SQL
- Create a Table If you haven’t already done so, create a table in your database. ...
- Define the Rules Next, define the rules for the case statement. ...
- Apply the Case Statement using SQL
Can we use case in update statement in SQL?
We can use a Case statement in SQL with update DML as well. Suppose we want to update Statecode of employees based on Case statement conditions. In the following code, we are updating statecode with the following condition. Similarly, it is asked, can case be used in update statement?
How do you use case when SQL?
- If no value/condition is found to be TRUE, then the CASE statement will return the value in the ELSE clause.
- If the ELSE clause is omitted and no condition is found to be true, then the CASE statement will return NULL.
- Conditions are evaluated in the order listed. ...
What is a case clause in SQL?
SQL CASE. The CASE is a statement that operates if-then-else type of logical queries. This statement returns the value when the specified condition evaluates to True. When no condition evaluates to True, it returns the value of the ELSE part.
Can I use SELECT statement in CASE statement 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. You can make any conditional statement using any conditional operator (like WHERE ) between WHEN and THEN .
Is SELECT statement case sensitive?
Keywords in SQL are case-insensitive for the most popular DBMSs. The computer doesn't care whether you write SELECT , select, or sELeCt ; so, in theory, you can write however you like.
What is the syntax for SELECT case?
Syntax of Select Case Statement in VB.Net your_expression: this denotes an expression which evaluates to one of the elementary Data Types supported in Microsoft VB.NET. expression_list: expression clauses that denote the match values for the expression. For the case of multiple clauses, separate them using a comma (,).
How do you give multiple conditions in a case in SQL?
Here are 3 different ways to apply a case statement using SQL:(1) For a single condition: CASE WHEN condition_1 THEN result_1 ELSE result_2 END AS new_field_name.(2) For multiple conditions using AND: CASE WHEN condition_1 AND condition_2 THEN result_1 ELSE result_2 END AS new_field_name.More items...•
Does SQL ignore case?
The default collations used by SQL Server and MySQL do not distinguish between upper and lower case letters—they are case-insensitive by default.
How do I select uppercase in SQL?
The UPPER() function converts a string to upper-case.
How do you end a select case?
If the code within a Case or Case Else statement block does not need to run any more of the statements in the block, it can exit the block by using the Exit Select statement. This transfers control immediately to the statement following End Select .
How are CASE statement and with select 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.
What is the last statement of a select case set of statements?
Each Select Case statement must have a matching End Select statement. The expression list that follows the Case in a Select Case statement must be a list of constant numeric or string expressions. If you want to use variables for different cases, use the If...Then... Else Statement instead.
What are the two types of case expressions?
CASE is used to specify a result when there are multiple conditions. There are two types of CASE expressions: simple and searched. In simple CASE expressions, an expression is compared with a value.
Can we use aggregate function in CASE statement?
CASE statement in SQL and aggregate functions Aggregate functions in SQL Server perform calculations and return a single value. Examples of aggregate functions are MIN, MAX, COUNT, ABG and CHECKSUM. For this purpose, we use the COUNT aggregate function in SQL Server.
Can a CASE statement have multiple conditions?
Multiple conditions in CASE statement You can evaluate multiple conditions in the CASE statement.
Does SQL care about capitalization?
All Caps SQL Commands For readability, all SQL commands should be written in uppercase letters. This allows the reader to identify the keywords in the SQL statement and easily determine what the query is executing.
Is MySQL SELECT case-sensitive?
Table names are stored in lowercase on disk and name comparisons are not case-sensitive. MySQL converts all table names to lowercase on storage and lookup. This behavior also applies to database names and table aliases.
Is SQL case-sensitive for column names?
MS SQL Server The column names in a select statement are not case sensitive even if quoted.
How do you make a SQL query not case-sensitive?
Case insensitive SQL SELECT: Use upper or lower functions or this: select * from users where lower(first_name) = 'fred'; As you can see, the pattern is to make the field you're searching into uppercase or lowercase, and then make your search string also be uppercase or lowercase to match the SQL function you've used.
What is a case statement in SQL?
The Case statement in SQL provides flexibility in writing t-SQL for DDL and DML queries. It also adds versatility to SQL Server queries. You should practice the Case statement in your queries.
What happens if you change the condition in a case statement in SQL?
Similarly, if we change the condition in a Case statement in SQL, it returns appropriate expression. In the following example, we want to get Product name for ProductID 4.it does not satisfy Case statement condition; therefore, it gave output from Else expression.
What clause contains i with the condition to get the required output?
In the following query, you can see that we have Group By clause and it contains i with the condition to get the required output.
How to evaluate a condition in SQL?
In this format of a CASE statement in SQL, we can evaluate a condition using comparison operators. Once this condition is satisfied, we get an expression from corresponding THEN in the output.
Can you insert data into SQL?
We can insert data into SQL tables as well with the help of Case statement in SQL. Suppose we have an application that inserts data into Employees table. We get the following values for gender.
Can you use a case statement with a group by clause?
We can use a Case statement with Group By clause as well. Suppose we want to group employees based on their salary. We further want to calculate the minimum and maximum salary for a particular range of employees.
Can you use order by clause in SQL?
We can use Case statement with order by clause as well. In SQL, we use Order By clause to sort results in ascending or descending order.
What is CASE Statement in SQL Server?
CASE Statement in SQL Server is the extension of IF…ELSE statement. Unlike IF…ELSE, where only the maximum of one condition is allowed, CASE allows the user to apply multiple conditions to perform different sets of actions in MS SQL. It returns a corresponding value associated with the condition defined by the user.
What is query 2?
Query 2: SEARCHED CASE with the ELSE option.
What does Boolean_Expression_1 mean?
The parameter Boolean_Expression_1, …denotes the expression which will be evaluated for TRUE or FALSE.
What is the parameter case_expression?
The parameter Case_Expression denotes the expression which we will eventually be compared to Value_1, Value_2, …
What happens if case expression does not match with value?
If Case_Expression does not match with Value_1, then Case_Expression is compared with Value_2 for equivalency. This process of comparing Case_Expression with Value will continue until Case_Expression finds matching equivalent value from the set of Value_1, Value_2,…
What happens if Boolean_expression_1 is false?
If Boolean_expression_1 is FALSE, then Boolean_expression_2 is evaluated for TRUE condition. This process of assessing Boolean_expression will continue until one of the Boolean_expression returns TRUE.
What is case expression?
The Case_Expression is compared with Value, in order starting from the first value, i.e., Value_1. Below is the execution approach:
What is a case statement in SQL Server?
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 . In this article, you use case with an update statement. So let's have a look at a practical example of how to use a case with Update statement in SQL Server 2012. The example is developed in SQL Server 2012 using the SQL Server Management Studio. We'll start by walking through a simple case statement.
What is a simple case expression?
The Simple Case expression checks only for equivalent values and cannot contain Boolean expressions. A Simple Case Expression looks for the first expression in the list of all the "when" clauses that matches the expression and evaluates the corresponding when clause. If there is no match, then the else clause is evaluated (if it exists). The general syntax of the Simple CASE expression is:
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.
Demo Database
Below is a selection from the "OrderDetails" table in the Northwind sample database:
SQL CASE Examples
The following SQL goes through conditions and returns a value when the first condition is met:
Example 1: Multiple Conditions using AND
Let’s now review an example with multiple conditions, where the rules are:
Example 2: Multiple Conditions and Results
For the final section of this guide, let’s review an example with multiple condition and results, where the rules are:
