6/21/2023 0 Comments Decode oracleYou can see that the data type of the DECODE is 1, whereas the two CASE statements "return" a data type of 2. ![]() If we use the DUMP function to evaluate the data types returned you'll see what I mean: SQL> select dump(case 1 when 2 then null else 0 end) as simple_caseĢ, dump(case when 1 = 2 then null else 0 end) as searched_caseģ, dump(decode(1, 2, null, 0)) as decode It only appears that the result obtained from each statement is identical. , case when 1 = 2 then null else 0 end as searched_caseĭo the simple CASE expression and the DECODE function (and in specific circumstances the searched CASE expression) always return the same result? select case 1 when 2 then null else 0 end as simple_case These three statements all seem to return the same result, 0. If default is omitted,Īs the searched CASE expression can be equivalent to the simple, this could be construed to be the same as well. No match is found, then Oracle returns default. To a search, then Oracle Database returns the corresponding result. Returns else_result if it exists and NULL otherwise.Ĭomparing this to the DECODE function, the descriptions seem to be identical.ĭECODE compares expr to each search value one by one. If no selector_value matches selector, the CASE expression The simple CASE expression returns the first result for which The documentation has the following to say about the simple CASE expression: This includes the expression, search, and result arguments.It seems like the simple CASE expression and the DECODE function are equivalent and that the results returned by them should be identical. Question: Is there a limit to the number of arguments that you can have in one DECODE statement? I'm getting an error, "ORA-00939: too many arguments for function".Īnswer: Yes, the maximum number of components that you can have in a DECODE function is 255. If yrs_of_service = 1 and 5 then return 0.06Īnswer: You will need to create a formula that will evaluate to a single number for each one of your ranges.ĭECODE(TRUNC (( yrs_of_service + 3) / 4), 0, 0.04, Question: I need to write a DECODE statement that will return the following: The formula will evaluate to 2, if the supplier_id is between 21 and 30. The formula will evaluate to 1, if the supplier_id is between 11 and 20. The formula will evaluate to 0, if the supplier_id is between 1 and 10. In this example, based on the formula: TRUNC ((supplier_id - 1) / 10 However, you can try to create a formula that will evaluate to one number for a given range, and another number for the next range, and so on.ĭECODE(TRUNC ((supplier_id - 1) / 10), 0, 'category 1', ![]() Question: I would like to know if it's possible to use the DECODE function for ranges of numbers, ie 1-10 = 'category 1', 11-20 = 'category 2', rather than having to individually decode each number.Īnswer: Unfortunately, you can not use the DECODE function for ranges of numbers. The date example above could be modified as follows: LEAST(date1, date2) Helpful Tip #2: One of our viewers suggested using the LEAST function (instead of the DECODE function) as follows: Sales Bonuses DECODE(SIGN(actual-target), -1, 'NO Bonus for you', 0,'Just made it', 1, 'Congrats, you are a winner') The SIGN/DECODE combination is also helpful for numeric comparisons e.g. The date example above could be modified as follows: DECODE(SIGN(date1-date2), 1, date2, date1) Helpful Tip #1: One of our viewers suggested combining the SIGN function with the DECODE function as follows: ![]() The formula below would equal 0, if date1 is greater than date2: (date1 - date2) - ABS(date1 - date2) ![]() Otherwise, the DECODE function should return date1.Īnswer: To accomplish this, use the DECODE function as follows: DECODE((date1 - date2) - ABS(date1 - date2), 0, date2, date1) Question: One of our viewers wanted to know how to use the DECODE function to compare two dates (ie: date1 and date2), where if date1 > date2, the DECODE function should return date2.
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