SQL DECODE function

SQL > Advanced SQL > DECODE FunctionDECODE is a function in Oracle and is used to provide if-then-else type of logic to SQL. It is not available in MySQL or SQL Server. The syntax for DECODE is: SELECT DECODE ( "column_name", "search_value_1", "result_1", ["search_value_n", "result_n"], {"default_result"} ); "search_value" is the value to search for, and "result" is the value that is displayed. For example, assume we have the following Store_Information table, Table Store_Information Store_Name Sales Txn_Date Los Angeles 1500 Jan-05-1999 San Diego 250 Jan-07-1999 San Francisco 300 Jan-08-1999 Boston 700 Jan-08-1999 if we want to display 'LA' for 'Los Angeles', 'SF' for 'San Francisco', 'SD' for 'San Diego', and 'Others' for all other cities, we would issue the following SQL, SELECT DECODE (Store_Name,   'Los Angeles', 'LA',   'San Francisco', 'SF',   'San Diego', 'SD',   'Others') Area, Sales, Txn_Date FROM Store_Information; "Area" is the name given to the column with the DECODE statement. Result: Area Sales Txn_Date LA 1500 Jan-05-1999 SD 250 Jan-07-1999 SF 300 Jan-08-1999 Others 700 Jan-08-1999 To achieve what DECODE does in MySQL and SQL Server, we would use the CASE function.