我应该使用哪个 SQL 查询？

Question

Given a list containing

Province, CustomerName, SalesValue

sorted by Province and CustomerName , describe an algorithm you could use that would output each CustomerName and SalesValue with the total SalesValue per Province .

Answer 1

You could first create a temporary table temp_table from your table list and use than GROUP BY .

SELECT CustomerName, Province, Sum(SalesValue) from list A
  INNER JOIN temp_table B 
  ON A.CustomerValue = B.CustomerValue
  GROUP BY CustomerName, Province