![]() ![]() O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers. A decode function basically performs the task of CASE statements. It compares a given expression with each search value one by one and returns a result on the basis of outcomes received from the comparison. DECODE is similar to the IF-THEN-ELSE and CASE expressions. DECODE function in Standard Query Language (SQL) is used to add procedural IF THEN ELSE like statements to a query. Get Mastering Oracle SQL now with the O’Reilly learning platform. 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. You are here: SQL Reference Manual > SQL Functions > String Functions > DECODE. 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. Even better might be with some explicit examples for if/then/else. 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 The DESC command is used to sort the data returned in descending order. DECODE () allows you to perform if-then-else logic in SQL without having to use PL/SQL. 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 Examplesįrom MariaDB 10.3.Performing aggregations over a finite set of values, such as days of If no matches are found, the default expression is returned, or NULL if no default is provided.ĭECODE_ORACLE is a synonym for the Oracle-mode version of the function, and is available in all modes. If it finds a match, the corresponding result expression is returned. If the first result is NULL, then the return value is converted. SQL Query formatter is not easy to do manually and it takes time to maintain these standards for each database schema. If the NULL keyword is used as an argument in the DECODE function, it must be cast to a data type that is appropriate for comparison. It preserves all the details of the original, just in a different format. The DECODE function is similar to the CASE expression, with the exception of how DECODE handles null values: A null value in expression1 will match a corresponding null value in expression2. In Oracle mode from MariaDB 10.3.2, DECODE compares expr to the search expressions, in order. The Oracle decode statement can be used in PL/SQL and it was developed to allow us to transform data values at retrieval time. The DECODE function returns a value that is the same datatype as the first result in the list. SQL formatter is a utility that converts the unreadable SQL code into a readable format. The resulting string will be the original string only if pass_str is the same. crypt_str should be a string returned from ENCODE(). In the default mode, DECODE decrypts the encrypted string crypt_str using pass_str as the In all modes from MariaDB 10.3.2: DECODE_ORACLE(expr, search_expr, result_expr ) It compares a given expression with each. In Oracle mode from MariaDB 10.3.2: DECODE(expr, search_expr, result_expr ) The Oracle decode and case functions are used within the Oracle database to transform data values for one value to another. DECODE function in Standard Query Language (SQL) is used to add procedural IF THEN ELSE like statements to a query. ![]()
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