How to Use Case Statement In Oracle?

In Oracle, the CASE statement is used to define a condition and return a specific value based on that condition. The syntax of a simple CASE statement is as follows:

CASE WHEN condition1 THEN result1 WHEN condition2 THEN result2 ... ELSE default_result END

You can also use the searched CASE statement, where you specify multiple conditions for evaluation. The syntax is as follows:

CASE WHEN condition1 THEN result1 WHEN condition2 THEN result2 ... ELSE default_result END

The CASE statement can be used in SELECT, WHERE, and ORDER BY clauses to handle conditional logic and return different values based on specified conditions. It is a powerful tool for data manipulation and transformation in Oracle SQL queries.

How to handle multiple conditions in a case statement in oracle?

In Oracle, you can handle multiple conditions in a case statement by using the following syntax:

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CASE
    WHEN condition1 THEN result1
    WHEN condition2 THEN result2
    ...
    ELSE default_result
END

You can specify multiple conditions and corresponding results within the CASE statement. The CASE statement evaluates each condition in order and returns the result corresponding to the first condition that is true. If none of the conditions are true, the ELSE clause provides a default result.

Here is an example of how you can use a CASE statement with multiple conditions in Oracle:

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SELECT 
    CASE 
        WHEN salary < 50000 THEN 'Low'
        WHEN salary BETWEEN 50000 AND 100000 THEN 'Medium'
        ELSE 'High'
    END AS salary_level
FROM employees;

In this example, the CASE statement evaluates the salary of each employee and returns a corresponding salary level based on the given conditions.

What is a case expression in oracle?

A case expression in Oracle is a conditional expression that allows you to perform different actions based on one or more conditions. It evaluates a set of conditions and returns a result based on the first condition that is met. It is similar to the switch statement in other programming languages.

The syntax of a simple case expression in Oracle is as follows:

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CASE
    WHEN condition1 THEN result1
    WHEN condition2 THEN result2
    ...
    ELSE default_result
END

Here, the CASE keyword is followed by one or more WHEN clauses, each specifying a condition and the corresponding result. The result that corresponds to the first condition that evaluates to true is returned. If none of the conditions are met, the default result specified in the ELSE clause is returned.

Case expressions can be used in SELECT, WHERE, ORDER BY, and other SQL statements to provide conditional logic in queries.

What is a case statement in PL/SQL?

A case statement in PL/SQL is a control structure that evaluates a specific expression and then executes a block of code based on the result of that evaluation. It is similar to a switch statement in other programming languages. It consists of a selector value and a series of WHEN-THEN clauses that define the conditions and corresponding actions to be taken. The case statement can also include an optional ELSE clause to handle situations where none of the specified conditions are met.

What is the default behavior of a case statement in oracle when no conditions are met?

In Oracle, if none of the conditions in a CASE statement are met, the default behavior is to return the NULL value.

What is a searched case statement in oracle?

A searched case statement in Oracle is a type of conditional statement that allows you to perform multiple comparisons and execute different code blocks based on the result of those comparisons.

In a searched case statement, each when clause contains a condition that is evaluated, and the corresponding code block is executed if the condition is true. If none of the conditions are met, the else block (if provided) is executed.

Here is an example of a searched case statement in Oracle:

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SELECT
    CASE
        WHEN salary > 50000 THEN 'High'
        WHEN salary > 30000 THEN 'Medium'
        ELSE 'Low'
    END AS salary_range
FROM
    employees;

In this example, the searched case statement evaluates the salary of each employee and assigns a salary range based on the value of the salary. If the salary is greater than 50,000, the range is 'High', if it is greater than 30,000 but less than or equal to 50,000, the range is 'Medium', and if it is less than or equal to 30,000, the range is 'Low'.