CODEWITHSUNDEEP
c#
amjad
amjad

Reputation: 13

How to find column existence in data table in C#?

I have problem. I have 2 queries in a stored procedure. Both run on certain condition if condition is true query one executes and returns 7 columns from 3 tables. If condition fail 2nd query returns 4 columns.

On front end I use a datatable to store query result. I assign values to textbox from datatable.

like

dt is data table name

Txt_name.Text=dt.Rows[0][6].ToString();

problem is that when 2nd query executes an error occurs. No columns exists at 6.

How I find dt has column at at index 6 or not?

Upvotes: 1

Views: 819

Answers (3)

user1542538
user1542538

Reputation:

Try this code

 int indx = 6;
 if(dt != null and dt.Columns.Count > indx)
 {
     Txt_name.Text=dt.Rows[0][indx].ToString();
 }

Upvotes: 2

Independent
Independent

Reputation: 2987

Do you have access to modify the stored procedure? And also manage all resources that use this stored procedure? I would recommend that it return the same structure regardless of the result.

If there is a false result, just have the additional fields empty. You can achieve this with the COALESCE operator, which return a given value (as '' in case of empty string) if there is NULL (i.e. no records in joined table).

A function that behave different base on a fields-count will nearly works as a Insurance to break the code in future. There will be a magic number "6" which can make behavior of the if-else-clause invert or always evaluate same result. If the stored procedure HAVE to return different structures, evaluate true/false first an then call the adequate stored procedure.

Upvotes: 0

Kundan Singh Chouhan
Kundan Singh Chouhan

Reputation: 14282

You can check the colums count something like below:

int index = 6;
Txt_name.Text = dt.Columns.Count > index ? dt.Rows[0][index].ToString() : String.Empty;

Upvotes: 1

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