6/18/2023 0 Comments Oracle db decode![]() ![]() Let us see some more complex examples of using Decode Function in SQL Loader Control file in future posts. SQL string for column : "decode(:PHONE_MAKE, 'Samsung', 'S', 'E')" PHONE_DESCRIPTION FIRST *, O(") CHARACTER Insert option in effect for this table: INSERTĬolumn Name Position Len Term Encl Datatype It works similar to an IF statement within other languages. It allows you to provide a value, and then evaluate other values against it and show different results. It’s similar to a CASE statement, but CASE is a statement where DECODE is a function. Table MOBILEPHONE, loaded from every logical record. The purpose of the Oracle DECODE function is to perform an IF-THEN-ELSE function. The log file for this load example is shown below The output is on the expected lines in the table as shown below All rights reserved.Ĭommit point reached - logical record count 8 Simple, isn't? Run this example using SQL Loader command line as shown belowĬ:\ sqlldr>sqlldr control=test.ctl log=test.log PHONE_ABB "decode(:PHONE_MAKE, 'Samsung', 'S', 'E')") => Decode logic used in SQL Loader Control File to load data based on a condition The control file example for this scenario is provided belowįields terminated by ',' optionally enclosed by '"' This means, we have to use DECODE logic while loading data for the third column. Now, the column PHONE_ABB takes a value of "S" if the MAKE is Samsung and E for all other cases. If expression1 is equal to expression2, or both expression1 and expression2 are null. This data needs to be loaded into a table MOBILEPHONE using SQL Loader, the structure of which is shown below The DECODE function compares each expression2 to expression1. We have a test data as shown below for explaining Decode Usage: Let us setup a simple test case with some data which we will insert into a table through SQL Loader. If expr is equal to a search, then Oracle Database returns the corresponding result. In order to use the sign function, we first need to map the "Low" range to negative numbers, the "Medium" range to 0, and the "High" range to positive numbers.In this short blog post, we will explain how to use Decode Function in the control file of SQL Loader to Load data. DECODE compares expr to each search value one by one. As we have 3 ranges, we need 3 values, and there is a SQL function that returns exactly 3 possible values (and was already supported back then) - the sign function. However, in addition to accepting a binary RAW for its input, it also returns a binary RAW for its output. I want to turn binary into something I can more easily port across systems. ![]() The function automatically converts e to the data type of s1 before. 5 Oracle has a function for encoding a binary value, specifically a RAW type, into base64: BASE64ENCODE. The first argument e is the value to be searched. We just need to convert each range to some unique discrete value. Oracle DECODE () function syntax Arguments. ![]() pick your encryption algorithm, your key, etc.). One option is to write a PL/SQL function that gets X as the input and returns the rank as the output.īut could we have a pure SQL solution? DECODE doesn't look like a good fit, because it works with discrete values, not with ranges. 5 Answers Sorted by: 8 If you want to write your own functions to encrypt and decrypt data, you would simply want to call the DBMSCRYPTO encrypt and decrypt methods with appropriate parameters (i.e. With a (Searched) CASE Expression it’s as simple as this: One of the most amazing features of the case the decode statements is that they allow us to create an index on data column values that do not exist in the database. This rank is determined by the value of X and two thresholds – LOW_TH and HIGH_TH. The decode and case functions are used within the Oracle database to transform data values for one value to another. This reminded me of a trick I came up with many years ago, probably before 8i ?Ī table T has a column X, and we need a query that one of the items it returns is a rank – either “Low”, “Medium” or “High”. As Tim wrote:ĬASE expressions were first released in Oracle 8i Prior to that if we wanted something similar to a CASE expression in our SQL, we had to use the DECODE function. I need to list all undo tablespace names in an Oracle (19c) database (regardless of whether theyre used or not) from the ts table. One of these examples is DECODE and CASE Expressions.
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