从数据库中删除记录时出错

Question

我需要一些关于从数据库中删除记录的帮助。

我正在尝试从我的 SQL Server 数据库中的表中删除一条记录。

我错过了什么吗？

  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

Answer 1

DataRow.Delete 不会从数据库中删除该行。它将DataRow 的RowState 标记为deleted。如果您致电Update，这将通过DataAdapter 进行检查。如果它的状态是Deleted，它将根据您必须提供的DeleteCommand 查找它。

所以你需要为你的DataAdapter 提供一个DeleteCommand，这是从数据库中删除行的sql。

Answer 2

你想删除它

_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"))

来源：Deleting a record from dataset and sql server

Answer 3

您将表格称为_DataSet.Tables(0)，然后将其称为_DataSet.Tables("0") 我敢打赌两者之一是不正确的。