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For example, you can use the CASE expression in statements such as SELECT, UPDATE, or DELETE, and in clauses like SELECT, WHERE, HAVING, and ORDDER BY. Oracle CASE expression has two formats: the simple CASE expression and the searched CASE expression. Both formats support an optional ELSE clause.
You can rewrite it to use the ELSE condition of a CASE: SELECT status, CASE status WHEN 'i' THEN 'Inactive' WHEN 't' THEN 'Terminated' ELSE 'Active' END AS StatusText FROM stage.tst
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.
2 Ιουν 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. What Does the SQL CASE Statement Do? SQL CASE Statement Syntax. Parameters of the CASE Statement.
The following example shows a simple CASE statement. Notice that you can use multiple statements after a WHEN clause, and that the expression in the WHEN clause can be a literal, variable, function call, or any other kind of expression. DECLARE. n number := 2; BEGIN. CASE n. WHEN 1 THEN dbms_output.put_line('n = 1');
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.
7 Δεκ 2023 · If you want to do if-else-then logic in select, where or anywhere else in a statement, you need a case expression. This is a series of when clauses that the database runs in order: For example, if you want to map exam correct percentages to grade letters according to these rules:
