how to add column in datatable in c# with default value c#?

Abhilash J A

10y30.1kVisual Basic .NET

Sir,

adp.Fill(ds);

After fill the database items, I want to add extra coloum with new arraylist values

DataRow drr = ds.Tables[0].NewRow();

ds.Tables[0].Columns.Add("Column1", typeof(string));

ArrayList listArr = new ArrayList();

listArr.Add(SchemeColorValues.Accent1);

listArr.Add(SchemeColorValues.Accent2);

listArr.Add(SchemeColorValues.Accent3);

listArr.Add(SchemeColorValues.Accent4);

foreach (var data in listArr)

{

//How can fill listArr each value here to datatable coloum name 'Column1'?

}

dt = ds.Tables[0];

Kindly replay me.

6 Replies

Know the answer? Post it — somebody with the same question will find it here.

Ehsan Sajjad10y ago
Accepted answer
You need to create new row in the loop and add value for the column. You can take a look at :

https://msdn.microsoft.com/en-us/library/z16c79x4(v=vs.110).aspx

Your code would be like:
ds.Tables[0].Columns.Add("Column1",typeof(string));
ArrayListlistArr=newArrayList();
listArr.Add(SchemeColorValues.Accent1);
listArr.Add(SchemeColorValues.Accent2);
listArr.Add(SchemeColorValues.Accent3);
listArr.Add(SchemeColorValues.Accent4);
foreach(variteminlistArr)
{
DataRowdr=ds.Tables[0].NewRow(); // add new row
dr["Column1"]=item; now set value for the column1
}
dt=ds.Tables[0];
Baparoutu Varma5y ago
You can try somethign like below:
try
{
   DataSet DS = GetResultsDS(sql); //Execute query and getting result in DataSet.
    if (DS != "" && DS  != null)
    {
        DS.Tables[0].Columns.Add("DrillDown", typeof(System.String)); //Adding column of string type
        foreach (DataRow row in DS.Tables[0].Rows)
        {
            row["DrillDown"] = "Value for new column"; // setting value
        }
    }
}
catch (Exception e)
{
    logger.Error(e);
}
Source : http://sforsuresh.in/how-to-add-a-column-to-datatable
Jayesh Vaghasiya8y ago
1. DataTable myNewTable = _BOFilmPrd.DS.Tables[_BOFilmPrd.TableFilmTrn].Select("SR_NO = " + txtSrNo.Text).CopyToDataTable();
2. bool AddEmpName = false;
3. bool AddDispName = false;
4. for (int i = 0; i < myNewTable.Columns.Count; i++)
5. {
6. if (myNewTable.Columns[i].ColumnName.ToString() == "EMP_NAME")
7. {
8. AddEmpName = true;
9. }
10. if (myNewTable.Columns[i].ColumnName.ToString() == "DISPNAME")
11. {
12. AddDispName = true;
13. }
14. }
15. if (AddEmpName == false)
16. myNewTable.Columns.Add("EMP_NAME", typeof(string));
17. if (AddDispName == false)
18. myNewTable.Columns.Add("DISPNAME", typeof(string));
19. foreach (DataRow row in myNewTable.Rows)
20. {
21. row["EMP_NAME"] = "JAYESH";
22. row["DISPNAME"] = "TEST";
23. }

Abhilash J A10y ago

Sir,

I can get an answer through modifying code.

dt = ds.Tables[0];
DataColumn newColumn = new DataColumn("Column1", typeof(string));
newColumn.AllowDBNull = true;
dt.Columns.Add(newColumn);
ArrayList listArr = new ArrayList();
listArr.Add(SchemeColorValues.Accent1);
listArr.Add(SchemeColorValues.Accent2);
listArr.Add(SchemeColorValues.Accent3);
listArr.Add(SchemeColorValues.Accent4);
listArr.Add(SchemeColorValues.Accent5);

int j = 0;
foreach (DataRow row in dt.Rows)
{
row["Column1"] = listArr[j];
j = j + 1;
}

Regards,

Abhilash.J.A

Ehsan Sajjad10y ago

You don't need to add dt.Rows.Add(dr); as that row is already in that datatable , just remove it and it should work.

Abhilash J A10y ago

Hello Ehsan Sajjad,

Very thank you for replay me...

Still I can not add arrlist items in the datatable's coloum name (that is, Column1),

There is showing empty values in Column1 field.

I have rewritten code like this,

foreach (var item in listArr)

{

DataRow dr = ds.Tables[0].NewRow();

dr["Column1"] = item;

dt.Rows.Add(dr);

}

Then it occurred error ('This row already belongs to another table.')

Regards,

Abhilash