This row already belongs to this table vb.net

Question

4.00/5 (1 vote)

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I just want to avoid duplicate data in my datatable.
The error points at

VB

dt.Rows.Add(row)

What is wrong in my code?

SQL

Dim dtSH As DataTable = wfms.formflow.getshopheadbycostcentreid(CostCtr)
 
For i As Integer = 0 To dtSH.Rows.Count - 1

   Dim row As DataRow = dt.NewRow()
   row = dt.NewRow()

    If dt.Rows.Count <> 0 Then

'loop each dt.rows'
      For countrow As Integer = 0 To dt.Rows.Count - 1 

'to determine whether new row equals data in dt'
        If dt.Rows(countrow)("EMPID_T").ToString <> row("EMPID_T").ToString Then

               row("EMPID_T") = dtSH.Rows(i)("EMPID_T")
               row("NAME_T") = dtSH.Rows(i)("NAME_T")
               dt.Rows.Add(row)

         End If

       Next

Else
                  row = dt.NewRow()
                  row("EMPID_T") = dtSH.Rows(i)("EMPID_T")
                  row("NAME_T") = dtSH.Rows(i)("NAME_T")
                  dt.Rows.Add(row)
End If


Next

/// update:

All I want to do is actually retrieve the distinct data and bind into dt. Is there any method to select distinct data into datatable using vb code without using SQL?

Posted 27-Jul-12 16:34pm

snamyna

Updated 27-Jul-12 16:54pm

v2

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Comments

[no name] 27-Jul-12 23:09pm

Well you could always use LINQ... it looks like SQL and gets translated to SQL but is not SQL.

Kenneth Haugland 27-Jul-12 23:14pm

This could just as well be a standard vb program without any database, just a datatable...

2 solutions

Solution 1

I must have been on somthing...

Your code want as bad as I thought

VB

Dim dtNewRow As DataRow   
dtNewRow = resultsDataTable.NewRow()   
dtNewRow.Item("id") = 0   
dtNewRow.Item("name") = "Joe Blogs"  
resultsDataTable.Rows.Add(dtNewRow)

But Why do you have to For loops that goes through the row, isnt one enough? Cant the complete copy look like this:

VB

Dim dtSH As DataTable = wfms.formflow.getshopheadbycostcentreid(CostCtr)
 
            For i As Integer = 0 To dtSH.Rows.Count - 1
                  Dim row As DataRow = dt.NewRow()
                  row("EMPID_T") = dtSH.Rows(i)("EMPID_T")
                  row("NAME_T") = dtSH.Rows(i)("NAME_T")
                  dt.Rows.Add(row)
            next

And shouldnt that be all?

Posted 27-Jul-12 16:44pm

Kenneth Haugland

Updated 27-Jul-12 17:04pm

v3

Comments

snamyna 27-Jul-12 22:54pm

Aftr debugging, by removing dt.Rows.Add(row), the only data that in my datatable is the first data because it enters else structure in If dt.Rows.Count <> 0 Then.
Every data that enter If dt.Rows.Count <> 0 is not displayed.
I have updated my question clearly of what result actually I am looking for.

snamyna 27-Jul-12 23:10pm

The for loops is used because one input inserted, it may result in several rows.

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snamyna · Accepted Answer · 2012-07-27T17:08:00

Using looping in vb.code will decrease the system performance.
One way that comes to my mind is by filtering the datatable with distinct data.

Example:
Data in dt datatable:

//Add new row
ID 1
Name John

//Add new row
ID 2
Name Mary

//Add new row
ID 1
Name John

if bind dt to Gridview1 it becomes:

1 John
2 Mary
1 John

Implement this method to distinct the datatable:

VB

Dim dttbl As DataTable = dt.DefaultView.ToTable(True)

    GridView1.DataSource = dttbl
    GridView1.DataBind()

SO the result becomes:

1 John
2 Mary

This row already belongs to this table vb.net

2 solutions

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This row already belongs to this table vb.net

2 solutions

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Solution 2

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