Dealing with datatable compute method?

Question

0.00/5 (No votes)

See more:

I'm trying to use compute method like that

C#

object sumObject;
        sumObject = dtbasket.Compute("Sum(total)", "");
        lbltotal.Text = (sumObject.ToString());

but it gives me this error
Invalid usage of aggregate function Sum() and Type: String.

Please could any one help me on this or give me another solution???

thanx in advance.

Posted 25-May-12 9:36am

Sarah Mohammed77

Add a Solution

2 solutions

Add a Solution

Add your solution here

Treat my content as plain text, not as HTML

Preview 0

…

Existing Members

Sign in to your account

...or Join us

Download, Vote, Comment, Publish.

Your Email
Password
Forgot your password?

Your Email
This email is in use. Do you need your password?
Optional Password

I have read and agree to the Terms of Service and Privacy Policy
Please subscribe me to the CodeProject newsletters

When answering a question please:

Read the question carefully.
Understand that English isn't everyone's first language so be lenient of bad spelling and grammar.
If a question is poorly phrased then either ask for clarification, ignore it, or edit the question and fix the problem. Insults are not welcome.
Don't tell someone to read the manual. Chances are they have and don't get it. Provide an answer or move on to the next question.

Let's work to help developers, not make them feel stupid.

This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Wendelius · Answer 1 · 2012-05-25T09:47:00

Solution 1

The likeliest reason is that the column total in your data table is defined with a data type that cannot be summed. For example if total is a string field, it cannot be summed. Check the underlying data type and if needed, change it to proper data type.

Posted 25-May-12 9:47am

Wendelius

Comments

Sarah Mohammed77 25-May-12 16:49pm

I MAKE IT decimal now it give me this error
Syntax error in aggregate argument: Expecting a single column argument with possible 'Child' qualifier.

Wendelius 25-May-12 17:21pm

Can you post the code

Sarah Mohammed77 25-May-12 17:22pm

decimal total=Convert.ToDecimal (dtbasket.Rows[i]["total"]);
decimal sumObject;
sumObject = Convert.ToDecimal(dtbasket.Compute("Sum(" + total + ")", " "));
lbltotal.Text = (sumObject.ToString());

Wendelius 25-May-12 17:35pm

Ok, What I meant is that your data table definition most likely isn't using a type that can be summed.

Have a look at the definition for the columns in your data table. The column named total should be defined as decimal (if that's the actual data type).

Refer to DataColumn Constructor (String, Type)[^] and DataColumnCollection.Add Method (String, Type)[^]

Prosan · Answer 2 · 2012-05-25T19:16:00

compute method not work on string datatype. if you don't want to change datatype of your field than in query you can write like that:-

SQL

select  cast(isnull(FieldName,0)as  decimal) from TableName

than you can use Compute. it will not give any error. but if in your total field you have stored non numeric value it will not work.