vb.net中的SQL事务语句

Question

我正在制作一个链接到 Microsoft SQLServer 的项目，用于输入、删除、编辑有关客户和订单的数据。完整的系统可以工作，但是我被建议使用事务而不是常规 SQL 语句来添加/删除/编辑数据等。

问题是，我之前和过去几个小时的研究都没有使用过这些，我什至不知道如何开始使用它们。

谁能告诉我如何把下面的代码变成一个事务？

    Public Shared Function SaveNewPerson(ByVal firstName As String, lastName As String, ByVal age As Integer, ByVal postcode As String, m_cn As OleDbConnection)

    Dim Dc As New OleDbCommand
    Dc.Connection = m_cn

    m_cn.Open()

    Dc.CommandText = "INSERT INTO tblPerson([firstName], [lastName], [age], [postcode]) VALUES('" & firstName & "', '" & lastName & "', '" & age & "', '" & postcode & "')"

    Dc.ExecuteNonQuery()

    Dim personID As Integer

    Dc.CommandText = "SELECT @@IDENTITY"
    Dc.CommandType = CommandType.Text
    personID = CType(Dc.ExecuteScalar(), Integer)

    m_cn.Close()

End Function

Answer 1

我刚刚在学习 TSQL，看看这种代码是否适合你（注意你需要 Dim tr（如果你愿意，可以使用不同的变量名）并在多个地方使用它，但不像在某些语言中，您不需要为不同的方法设置对象。

  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

        Dim Dc As New OleDbCommand
        Dc.Connection = _con

        tr = _con.BeginTransaction()

        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

         Dim personID As Integer

        Dc.CommandText = "SELECT SCOPE_IDENTITY() AS personID"
        Dc.CommandType = CommandType.Text
        personID = CType(Dc.ExecuteScalar(), Integer)

        tr.Commit()

    Catch ex As Exception

        tr.Rollback()

        Throw
    End Try

End Function