如何在t-sql的表末尾添加总行？

Question

I need to add a row of sums as the last row of the table. For example:

   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

How can I do this? (T-SQL)

Answer 1

You can use 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;

However, count(*) will give you no of rows available in table, if the book_name has null value also, then you need count(book_name) instead of count(*) .

Answer 2

Try with 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

I find that grouping sets is much more flexible than rollup . I would write this as:

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), () );

Strictly speaking, the GROUPING function with a CASE is better than COALESCE() . However, NULL values on the grouping keys is quite rare.