Question

我的项目中有一个SQL插入查询，它工作正常，实际上可能有点太好了，因为它保存了我输入的数据，但保存了两次，每个都有两个不同的ID自动编号。任何人都可以找出原因吗？

//保存按钮代码

Private Sub buttonSave_Click(sender As Object, e As EventArgs) Handles btnSave.Click
    Dim incidentSolved As Boolean = False

    If cboxSolved.Checked Then
        incidentSolved = True
    End If

    If txtClientSave.Text = "" Then
        MsgBox("Client name cannot be blank")

    ElseIf rtbProblem.Text = "" Then
        MsgBox("Problem cannot be blank")

    ElseIf cboxSolved.Checked = True And rtbSolution.Text = "" Then
        MsgBox("Please enter solution")

    Else
        database.SaveNewIncident(txtClientSave.Text, dtpStart.Value, dtpEnd.Value, rtbProblem.Text, dtpStartTime.Value, dtpEndTime.Value, cboxSolved.Checked, rtbSolution.Text, _con)

        MsgBox("Save successful")

        txtClientSave.Text = ""
        rtbProblem.Text = ""
        rtbSolution.Text = ""
        dtpStart.Value = Date.Today
        dtpEnd.Value = Date.Today
        dtpStartTime.Value = DateTime.Now
        dtpEndTime.Value = DateTime.Now
        cboxSolved.Checked = False

    End If

    loadIncidents()

End Sub

//保存SQL

Public Shared Function SaveNewIncident(ByVal clientName As String, dateStart As Date, dateEnd As Date, ByVal incidentProblem As String, ByVal timeStart As String, ByVal timeEnd As String, ByVal incidentSolved As Boolean, ByVal incidentSolution As String, _Con As OleDbConnection)

    Dim tr As OleDbTransaction = Nothing

    Try
        tr = _Con.BeginTransaction()

        Dim Dc As New OleDbCommand
        Dc.Connection = _Con

        Dc.CommandType = CommandType.Text
        Dc.CommandText = "INSERT INTO dbo.tblIncidents VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?)"
        Dc.Transaction = tr
        Dc.Parameters.Add("@clientName", OleDbType.VarChar).Value = clientName
        Dc.Parameters.Add("@dateStart", OleDbType.Date).Value = dateStart
        Dc.Parameters.Add("@dateEnd", OleDbType.Date).Value = dateEnd
        Dc.Parameters.Add("@incidentProblem", OleDbType.LongVarChar).Value = incidentProblem
        Dc.Parameters.Add("@timeStart", OleDbType.VarChar).Value = timeStart
        Dc.Parameters.Add("@timeEnd", OleDbType.VarChar).Value = timeEnd
        Dc.Parameters.Add("@incidentSolved", OleDbType.Boolean).Value = incidentSolved
        Dc.Parameters.Add("@incidentSolution", OleDbType.LongVarChar).Value = incidentSolution
        Dc.Parameters.Add("@SSMA_TimeStamp", OleDbType.DBTimeStamp)

        Dim supportID As Integer
        Dim Ds As New OleDbCommand

        Ds.CommandType = CommandType.Text
        Ds.CommandText = "SELECT SCOPE_IDENTITY() AS supportID"
        Ds.Transaction = tr

        supportID = CType(Dc.ExecuteScalar(), Integer)
        Dc.ExecuteNonQuery()

        tr.Commit()

    Catch ex As Exception

        mdInit.errorLog(ex.Message, ex.StackTrace)
        MsgBox("Failed to save data, refer to error log")
        tr.Rollback()

    End Try

End Function

Answer 1

supportID = CType(Dc.ExecuteScalar(), Integer)
Dc.ExecuteNonQuery()   'you are doing it a second time here

就是这样，你正在执行它两次

评论你的第二个

     supportID = CType(Dc.ExecuteScalar(), Integer)
    'Dc.ExecuteNonQuery()

问题出在SaveNewIncident中，你执行标量并获得生成的supportId，然后你再次执行整个事件作为非查询 - 两者都是执行命令的有效方法，但INSERT和SELECT命令都执行两次（在第二个执行中，ExecuteNonQuery，你没有选择所选的值）

怎么样

Public Shared Function SaveNewIncident(ByVal clientName As String, dateStart As Date, dateEnd As Date, ByVal incidentProblem As String, ByVal timeStart As String, ByVal timeEnd As String,
                                   ByVal incidentSolved As Boolean, ByVal incidentSolution As String, _Con As OleDbConnection)

Dim tr As OleDbTransaction = Nothing

Try
    tr = _Con.BeginTransaction()

    Dim Dc As New OleDbCommand
    Dc.Connection = _Con

    Dc.CommandType = CommandType.Text
    Dc.CommandText = "INSERT INTO dbo.tblIncidents VALUES(?, ?, ?, ?, ?, ?, ?, ?, ?)"
    Dc.Transaction = tr
    Dc.Parameters.Add("@clientName", OleDbType.VarChar).Value = clientName
    Dc.Parameters.Add("@dateStart", OleDbType.Date).Value = dateStart
    Dc.Parameters.Add("@dateEnd", OleDbType.Date).Value = dateEnd
    Dc.Parameters.Add("@incidentProblem", OleDbType.LongVarChar).Value = incidentProblem
    Dc.Parameters.Add("@timeStart", OleDbType.VarChar).Value = timeStart
    Dc.Parameters.Add("@timeEnd", OleDbType.VarChar).Value = timeEnd
    Dc.Parameters.Add("@incidentSolved", OleDbType.Boolean).Value = incidentSolved
    Dc.Parameters.Add("@incidentSolution", OleDbType.LongVarChar).Value = incidentSolution
    Dc.Parameters.Add("@SSMA_TimeStamp", OleDbType.DBTimeStamp)

    Dim supportID As Integer
    Dc.CommandText += ";SELECT SCOPE_IDENTITY() AS supportID"

    supportID = CType(Dc.ExecuteScalar(), Integer)

    tr.Commit()

Catch ex As Exception

    mdInit.errorLog(ex.Message, ex.StackTrace)
    MsgBox("Failed to save data, refer to error log")
    tr.Rollback()

End Try

结束功能

ds和dc之间也存在混淆

Answer 2

只需评论Dc.ExecuteNonQuery()，因为它已在Dc.ExecuteScalar()

中执行查询

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2 个答案: