kyu6_SQL_Basics_simple_null_handling.sql

-- SQL Basics: Simple NULL handling
--
-- https://www.codewars.com/kata/5811315e04adbbdb5000050e/train/sql
--
-- For this challenge you need to create a SELECT statement, this select statement must have NULL handling, using
-- COALESCE and NULLIF;
--
-- If no name is specified you must replace with [product name not found];
-- If no card_name is specified you must replace with [card name not found];
-- If no price is specified you must throw away the record, you must also filter the dataset by prices greater than 50;
--
-- eusales table schema
--      id
--      name
--      price
--      card_name
--      card_number
--      transaction_date
--
-- resultant table schema
--      id
--      name
--      price (greater than 50.00)
--      card_name
--      card_number
--      transaction_date

SELECT id,
    COALESCE(NULLIF(name, ''), '[product name not found]') AS name,
    price,
    COALESCE(NULLIF(card_name, ''), '[card name not found]') AS card_name,
    card_number,
    transaction_date
FROM eusales WHERE price >= 50.0;