在vb.net中過濾來自數據集的記錄

Question

我想要來自數據集的過濾器值。它包含從零開始並且非零值爲的電話號碼。我如何過濾數據集中的電話號碼（從非零開始）。下面是vb.net代碼和由此產生的錯誤。

cmd = New OracleCommand("select PHONE from reports.renewal_contact_t where run_date=to_date('" + TextBox1.Text + "','mm/dd/yyyy') and EXP_DATE =to_date('" + TextBox2.Text + "','mm/dd/yyyy') and region not in('TNP')", cn) 
ada = New OracleDataAdapter(cmd) 
ada.Fill(ds, "reports.renewal_contact_t ") 
Dim ds1 As New DataSet 
ds1.Tables("reports.renewal_contact_t").DefaultView.RowFilter = "PHONE NOT like'0'" 

錯誤：對象引用不設置爲一個對象的一個​​實例。 rowfilter行中的錯誤

Answer 1

在您的ds1中有沒有表 * reports.renewal_contact_t *。將其更改爲

cmd = New OracleCommand("select PHONE from reports.renewal_contact_t where run_date=to_date('" + TextBox1.Text + "','mm/dd/yyyy') and EXP_DATE =to_date('" + TextBox2.Text + "','mm/dd/yyyy') and region not in('TNP')", cn) 
ada = New OracleDataAdapter(cmd) 
ada.Fill(ds, "reports.renewal_contact_t") 
' no need for a new dataset - as you fill ds (and not ds1)!! 
ds.Tables("reports.renewal_contact_t").DefaultView.RowFilter = "PHONE NOT like'0'" 

Answer 2

這將工作對一個數據集以「模式」類似

**數據例如> *

Id Value 

1 303-888-8888 
2 0-418-895-9598 

TryCast(filteredDS.Tables(0).Rows.Cast(Of DataRow).Where(Function(row) Not row.ItemArray(1).ToString().Substring(0, 1).Equals("0")), IEnumerable(Of DataRow)).ToList().ForEach(Sub(row) row.Delete()) 

--removes任何記錄在手機開始與除零之外的任何東西