CODEWITHSUNDEEP
c#
Shane
Shane

Reputation: 542

Checking if multiple rows exists when populating Data Table

I'm trying to populate a Data Table with a range of years to be used in a Data List. My application has five lists on the page and I have buttons to scroll through the years: 1995, 1996, 1997 and so on. However, if year 1997 does not exist in the database I get an error in my application: There is no row at position 2. How can I prevent this? if (dt.Rows.Count > 0) checks that data exists but how do I check that data exists before setting the value of the other strings (SecondYear, ThirdYear, FourthYear, FifthYear)

if (dt.Rows.Count > 0)
    {
        if (!string.IsNullOrEmpty(dt.Rows[0][0].ToString()))
        {
            FirstYear = dt.Rows[0][0].ToString();
        }
        if (!string.IsNullOrEmpty(dt.Rows[1][0].ToString()))
        {
            SecondYear = dt.Rows[1][0].ToString();
        }
        if (!string.IsNullOrEmpty(dt.Rows[2][0].ToString()))
        {
            ThirdYear = dt.Rows[2][0].ToString();
        }
        if (!string.IsNullOrEmpty(dt.Rows[3][0].ToString()))
        {
            FourthYear = dt.Rows[3][0].ToString();
        }
        if (!string.IsNullOrEmpty(dt.Rows[4][0].ToString()))
        {
            FifthYear = dt.Rows[4][0].ToString();
        }
    }

This does not work:

if (dt.Rows[1][0].Count > 0)
        {
            SecondYear = dt.Rows[1][0].ToString();
        }

Upvotes: 0

Views: 379

Answers (2)

sam
sam

Reputation: 1985

Instead of indexers, please try to use DataRowExtensions (or DataSetExtensions) as below

var o1 = dt.Rows[1].Field<string>(0);

or more readable using column name:

var o2 = dt.Rows[1].Field<string>("columnName");

Upvotes: 1

Magnus
Magnus

Reputation: 46909

Check that the nr. of rows are larger than or equal to the year row you are checking.

if(dt.Rows.Count >= 1) 
   SecondYear = dt.Rows[1][0].ToString();

Upvotes: 0

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