asked on

Sum in sql

Hello,
I need some help with coding in C#.
I'm trying to pull out a sum value from an access database. I'm pretty sure I have the sql statement correct cause I tried it in access itself. but when I ran it in visual studio I get an error msg. I know there is something wrong with my code, I just don't know how to correct it.
All I want it to do is go into the my access database and add up (sum) the numbers in the 'TotalDown' column and just return the number. I then will display that number in a textbox.
Please see attached.
Please help.
Capture.JPG

Kyle Abrahams, PMP

I would name the actual column:

eg:

select sum(totalDown) totalDown from ...

What do you get if you do this as a string?

[ fanpages ]

Hi,

string str = "SELECT sum(TotalDown) FROM Tasks WHERE TaskType=3 AND ScheduleStart between # " + dateTimePicker1.Text + "# AND # " + dateTimePicker2.Text

Did you have a final # character when you ran this SQL statement within an MS-Access query?

i.e.

SELECT
sum(TotalDown)
FROM
Tasks
WHERE
TaskType=3
AND
ScheduleStart between #(date here, preferably in [DD-MMM-YYYY] format)# AND #(another [DD-MMM-YYYY] format date here)#

BFN,

fp.

MrMay

ASKER

I'm sure the sql statment is correct. I've use it in another portion of my code, where I just use count to get the number of rows, but now I'm using the same sql statement to get the sum of the numbers in the column... I just don't know how to display the result.

[ fanpages ]

Does that mean the last # character is within the string, but we just cannot see it in your JPeG image?

MrMay

ASKER

re took the pic... please see attached.
Capture.JPG

[ fanpages ]

Thanks. Just a 'yes' response would have done though! :)

What is the value of dateTimePicker1.Text and dateTimePicker2.Text?

MrMay

ASKER

just randon.... I'm doing Oct 10 2013 to nov 12, 2013.

MrMay

ASKER

any date that I choose, I get the same error msg.
I think it has something to do with the fact that in the code... its row.count... and I'm doing a sum not a count.

Rajkumar Gs

Hi
1. Did you check the value in debug mode using quick watch ? I mean that in the right side of (int)
2. If it stills seems a number, just give a try by apply trim before casing. Suspecting Any space which makes it as a string which fails in casting?

Raj
From Mobile

MrMay

ASKER

Raj.. i don't understand....

MrMay

ASKER

Let me try to explain this again a bit more clearer.
Let's say I have an access table called Students, that looks like so.

Name Age
Mike 5
Kevin 2
Kelly 10

Now, I want to display the sum of the Age column. So the result would be 17.
My query statment would be.... select sum(Age) from Students.
Now, I want to display the result (the sum which is 17) in a textbox when a user presses a button. How can I write the c# that will do this?

Rajkumar Gs

1. Need to check the value of
ds.Tables["Tasks"].Rows[ds.Tables["Tasks"].Rows.Count - 1][0]
which is causing this error on casting to int
For this once you get the crash, try to find out the value using Quick watch feature of Visual Studio
or place mouse cursor over 'ds' which will popup option to view the contents of that dataset.

2. This one I meant as below
(int)ds.Tables["Tasks"].Rows[ds.Tables["Tasks"].Rows.Count - 1][0].trim();
not sure about this

Raj

Rajkumar Gs

I suggest to change your C# code by using ExecuteScalar which will be suitable to return single value.
<competing site link removed - GaryC123>

MrMay

ASKER

Hey Raj... I looked at that code in the link that u send....
I don't have the GetConnection. method like its in that example.
cmd1.Connection = GetConnection();

ASKER CERTIFIED SOLUTION

Kyle Abrahams, PMP

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Rajkumar Gs

GetConnection(); returns a connection. Instead of that you use a connection object directly

string connection = "your connection string";
OleDbConnection conn = new OleDbConnection(connection);
OleDbCommand cmd1 = new OleDbCommand();
cmd1.Connection = conn ;
cmd1.CommandText = "SELECT treatment FROM appointment WHERE patientid = " + text;
var result = cmd1.ExecuteScalar();

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