Αποτελέσματα Αναζήτησης
Oracle CASE expression allows you to add if-else logic to SQL statements without having to call a procedure. The CASE expression evaluates a list of conditions and returns one of the multiple possible results. You can use a CASE expression in any statement or clause that accepts a valid expression.
In a simple CASE expression, Oracle Database searches for the first WHEN... THEN pair for which expr is equal to comparison_expr and returns return_expr. If none of the WHEN... THEN pairs meet this condition, and an ELSE clause exists, then Oracle returns else_expr. Otherwise, Oracle returns null.
7 Δεκ 2023 · You can use a case expression like this: The database processes the expression from top-to-bottom. It returns the value for the first when clause that is true. If none are true (the percentage is less than 50 or null), it returns the value in the else clause which is F.
2 Ιουν 2023 · SQL CASE Statement Explained with Examples. 29 Comments / Last updated: June 2, 2023. The SQL CASE statement allows you to perform IF-THEN-ELSE functionality within an SQL statement. Learn more about this powerful statement in this article. This article applies to Oracle, SQL Server, MySQL, and PostgreSQL. Table of Contents.
Oracle Data Warehousing Guide for examples using various forms of the CASE expression. Simple CASE Example For each customer in the sample oe.customers table, the following statement lists the credit limit as "Low" if it equals $100, "High" if it equals $5000, and "Medium" if it equals anything else.
A simple CASE statement evaluates a single expression and compares the result with some values. The simple CASE statement has the following structure: CASE selector. WHEN selector_value_1 THEN . statements_1. WHEN selector_value_1 THEN . statement_2. ... ELSE . else_statements. END CASE;
Oracle Database 23c extended CASE expressions in PL/SQL to support dangling predicates in simple CASE expression. These work like regular simple CASE expressions - you have a single selector. Each WHEN clause may contain a comparison condition and the right-hand side of the formula.
