Question

我需要在表的最后一行添加一行求和。例如：

   book_name   |   some_row1   |   some_row2   |   sum   
---------------+---------------+---------------+----------
    book1      |   some_data11 |   some_data12 |   100
    book2      |   some_data21 |   some_data22 |   300
    book3      |   some_data31 |   some_data32 |   500
 total_books=3 |   NULL        |   NULL        |   900

我该怎么做？（T-SQL）

Answer 1

您可以使用union all：

select book_name, some_row1, some_row2, sum 
from table t
union all
select cast(count(*) as varchar(255)), null, null, sum(sum)
from table t;

但是，count(*)将为您提供表中的no of rows，如果book_name也具有null值，则您需要count(book_name)而不是{{ 1}}。

Answer 2

尝试使用ROLLUP

SELECT  CASE 
            WHEN (GROUPING([book_name]) = 1) THEN 'total_books'
            ELSE [book_name] END AS [book_name],some_row1, some_row2
        ,SUM(]sum]) as Total_Sales
From    Before
GROUP BY
        [book_name] WITH ROLLUP

Answer 3

我发现grouping sets比rollup更灵活。我将其写为：

select coalesce(book_name,
                replace('total_books=@x', '@x', count(*))
               ) as book_name,
       col2, col3, sum(whatever)
from t
group by grouping sets ( (book_name), () );

严格来说，带有GROUPING的{{1}}函数比CASE更好。但是，分组键上的COALESCE()值非常少。

如何在t-sql的表末尾添加总行？

3 个答案: