如何将数据库表的总和变为变量？

Question

I have a database table named Deposit and one of the column name in it is 30-12-2013 . The column has two values such as 54,26.

i want to get the sum of that column column into a variable. I use the following code:

con.Open();
SqlCeCommand cmd11 = con.CreateCommand();
cmd11.CommandText = "select sum(30-12-2013) from Deposit";
int result = ((int)cmd11.ExecuteScalar());
displaylabel.Text = result.ToString();
con.Close();

But, I am getting the value of variable 'result' as -3990.

Whats wrong with my code.. Please help me.. Thanks in advance..

Answer 1

(30-12-2013) * 2 (because you have two entries) = -1995 * 2 = -3990

You have to use:

SELECT sum([30-12-2013])
FROM   dbo.Deposit 

Answer 2

尝试为具有不寻常名称的列使用括号 -

cmd11.CommandText = "SELECT SUM([30-12-2013]) FROM Deposit";

Answer 3

This has already been answered so instead of answering your actual question I am going to propose an alternative solution.

Instead of having a table as follows:

SomeColumn | 30-12-2013 | 31-12-2013 | 01-01-2014
-----------+------------+------------+------------
    A      |    540     |    100     |    246
    B      |    130     |     90     |    377

Have a normalised table:

SomeColumn |    Date    | Amount 
-----------+------------+--------
   A       | 2013-12-30 |  540
   A       | 2013-12-31 |  100
   A       | 2014-01-01 |  246
   B       | 2013-12-30 |  130
   B       | 2013-12-31 |  90
   B       | 2014-01-01 |  377

This means you don't require a new column for every day. So your query would become:

SELECT  SUM(Amount) AS Amount
FROM    Deposit
WHERE   Date = '20131230';

And if you wanted to reproduce your original structure you can use:

SELECT  SomeColumn,
        SUM(CASE WHEN Date = '20131230' THEN Amount ELSE 0 END) AS [30-12-2013],
        SUM(CASE WHEN Date = '20131231' THEN Amount ELSE 0 END) AS [31-12-2013],
        SUM(CASE WHEN Date = '20140101' THEN Amount ELSE 0 END) AS [01-01-2014]
FROM    Deposit
GROUP BY SomeColumn;

Example on SQL Fiddle (Using SQL Server as it doesn't support SQL Server CE)