Αποτελέσματα Αναζήτησης
20 Νοε 2015 · 1) LEFT JOIN the JOBS table and then use your CASE statement. 2) Keep my CASE statement with your SELECT 1 FROM JOBS J WHERE J.ID_DOC = D.ID_DOC withount joining the JOBS table. Both perform good.
Learn how to use the Oracle CASE expression to add if-else logic to SQL statements without calling a procedure. See the syntax and examples of simple and searched CASE expressions, and how to use them in SELECT, UPDATE, and HAVING clauses.
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.
This Oracle tutorial explains how to use the Oracle / PLSQL CASE statement with syntax and examples. The Oracle / PLSQL CASE statement has the functionality of an IF-THEN-ELSE statement. Starting in Oracle 9i, you can use the CASE statement within a SQL statement.
EXISTS Condition. An EXISTS condition tests for existence of rows in a subquery. Description of the illustration exists_condition.eps. Table 6-11 shows the EXISTS condition.
In a simple CASE expression, Oracle 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 · How to use CASE for IF-THEN logic in SQL SELECT. If you want to see the grade for each exam, select the case expression like a regular column: It’s a good idea to give the expression an alias. This is particularly important if the case is in a subquery.
