Error while deleting record from database

问题

I need some help with delete record from database.

I am trying to delete a record from a table in my SQL Server database.

Am I missing something?

  Private Sub cmdDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdDelete.Click
     _DataSet.Tables(0).Rows(CInt(txtCurrent.Text) - 1).Delete()
     ' tho, it can remove the deleted rows
     ' we cannot call the DataSet.AcceptChanges method
     ' because the DataAdapter would not recognize the delete row
     ' by the time DataAdapter.Update(DataSet) is called.
     EnableNavigation()
     cmdSave.Enabled = True  ' let user update the underlying database
     ' after deleting the current record, the current record still points to the
     ' deleted record (though it cannot be updated). 
     ' The user must MoveNext/Back to view other records.
 End Sub

回答1:

DataRow.Delete does not delete this row from database. It marks the DataRow's RowState as deleted. This will be checked from a DataAdapter if you call Update. If it's state is Deleted it will look for its according DeleteCommand which you have to provide.

So you need to provide a DeleteCommand for your DataAdapter which is the sql to delete the row from the database.

回答2:

You want to Delete it

_DataSet.Tables(0).Rows(CInt(txtCurrent.Text) - 1).Delete()

 Dim adapter As New SqlDataAdapter
 Dim cmdBuilder As New SqlCommandBuilder(adapter)
 Dim DutyDetails As String = "SELECT * from MyTable"

 adapter.SelectCommand = New SqlCommand(DutyDetails, SQLConn)
 adapter.UpdateCommand = cmdBuilder.GetUpdateCommand
 adapter.DeleteCommand = cmdBuilder.GetDeleteCommand

 Dim cb As SqlCommandBuilder = New SqlCommandBuilder(adapter)

  adapter.Update(_DataSet.Tables("0"))

Source: Deleting a record from dataset and sql server

回答3:

You refer to the table as _DataSet.Tables(0), then refer to it later as _DataSet.Tables("0") I bet one of the two is incorrect.

来源：https://stackoverflow.com/questions/20612049/error-while-deleting-record-from-database

标签

sql

sql-server

vb.net

delete-record