3/27/2023 0 Comments Sql decode![]() If expression1 is equal to expression2, or both expression1 and expression2 are null. DECODE was Oracle's proprietary solution to conditional SQL before CASE was available. The syntax is: 1 1 DECODE ( expression, search, result, search, result. The DECODE function compares each expression2 to expression1. I.e., FIELD('A','A') and FIELD('a','A') both return 1. The DECODE function in Oracle allows you to have IF-THEN-ELSE logic in your SQL statements. ![]() Keep in mind that FIELD's output does not seem to be case sensitive. While I don't think this is the best solution to the question either in terms of performance or readability it is interesting as an exploration of MySQL's string functions. Database SQL Language Reference DECODE Syntax Description of the illustration decode.gif Purpose DECODE compares expr to each search value one by one. Select Name, IFNULL(ELT(FIELD(Age,ġ3, 14, 15, 16, 17, 18, 19),'Thirteen','Fourteen','Fifteen','Sixteen', The Decode function evaluates an expression to determine which criteria options are met and then performs an action (such as overriding a value) based on the. DECODE function in Standard Query Language (SQL) is used to add procedural IF THEN ELSE like statements to a query. IFNULL returns the default AgeBracket if no match to Age is found in the list. ) returns 'Fourteen', which is the 2nd argument of ELT (not counting the FIELD() argument). The SQL DECODE () function allows you to add procedure if-then-else logic to queries. ) returns 2 because 14 is the 2nd argument of FIELD (not counting Age). ELT() returns the string from ELTs argument list at the position provided by FIELD(). ![]() In the code that follows, FIELD() returns the argument list position of the string that matches Age. O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.Another MySQL option that may look more like Oracle's DECODE is a combination of FIELD and ELT. Get Mastering Oracle SQL now with the O’Reilly learning platform. decode (instr (idsegmento,'1'),0,'b','a') I'm assuming you want to match on a '1' anywhere in the field. An index for a table can help improve searches and optimizations. In order to transform this result set into a single row with fourĬolumns, we need to fabricate a column for each quarter of the yearĪnd, within each column, sum only those records whose order dateįalls in the desired quarter. Description: DECODE is a shortcut for the so-called simple CASE construct, in which a given expression is. The Decode function evaluates an expression to determine which criteria options are met and then performs an action (such as overriding a value) based on the evaluation results the function will perform these steps using a process that involves cases for different criteria. ![]() SELECT TO_CHAR(order_dt, 'Q') sales_quarter, SUM(sale_price) tot_sales FROM cust_order WHERE order_dt >= TO_DATE('0','DD-MON-YYYY') AND order_dt < TO_DATE('0','DD-MON-YYYY') GROUP BY TO_CHAR(order_dt, 'Q') ORDER BY 1 It is automatically converted to the data type of the first search value before comparing. The Oracle/PLSQL DECODE function has the functionality of an IF-THEN-ELSE statement. Syntax: DECODE (cryptstr, passstr) Arguments: Syntax Diagram: MySQL Version: 5. The week or months of the year, but you want the result set toĬontain one row with N columns rather than N rows with two columns.Ĭonsider the following query, which aggregates sales data for each Oracle / PLSQL: DECODE Function Description. MySQL DECODE () function decodes an encoded string and returns the original string. You can use this Decode function in various Oracle versions or PLSQL versions such as Oracle 9i, Oracle 10g, Oracle 11g and Oracle 12c. Performing aggregations over a finite set of values, such as days of A Decode function in SQL will be 255, which is the maximum permissible number of components including the expression argument, search argument and the result argument.
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