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29 Δεκ 2014 · TO_DATE with proper format model should do the trick. Let's stick to a format model first. SQL> alter session set nls_date_format='dd/mm/yyyy hh24:mi:ss'; Session altered. Now, let's use TO_DATE to explicitly convert the string literal to date.
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.
The syntax for the CASE statement in Oracle/PLSQL is: CASE [ expression ] WHEN condition_1 THEN result_1 WHEN condition_2 THEN result_2 ... WHEN condition_n THEN result_n ELSE result END Parameters or Arguments expression Optional. It is the value that you are comparing to the list of conditions.
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.
The CASE expression is like a more flexible version of the DECODE function. The value match CASE expression, or simple CASE expression, compares the value of the expression (DEPTNO), with the list of comparison expressions (10 - 40). Once it finds a match, the associated value is returned.
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.
15 Μαρ 2021 · You can use a SCALAR SUBQUERY - a query that returns zero or one rows with exactly one column. So this will work: 1* select case when dummy = 'X' then (select count(*) from all_users) else (select count(*) from dual) end cnt from dual ops$tkyte%ORA10GR2> / CNT ----- 46
