Question

以下代码段是否有更好的解决方案（使用更少的代码）。我发现自己在VB6中做了很多工作，希望能够减少它。

据我所知，Connection.Execute无法正常工作

    SQL = "SELECT SomeID FROM TableA"
    RecordSet.Open SQL, Connection, adOpenStatic, adLockOptimistic, adCmdText
    SomeID = RecordSet.Fields(0).Value
    RecordSet.Close

    SQL = "SELECT AnotherID FROM TableB"
    RecordSet.Open SQL, Connection, adOpenStatic, adLockOptimistic, adCmdText
    AnotherID = RecordSet.Fields(0).Value
    RecordSet.Close

这不是一个功能问题，只是想看看是否有更整洁的方式。

Answer 1

RecordSet.Open()和Connection.Execute()的默认参数为：

adOpenForwardOnly
ADLOCKREADONLY

您使用不同的设置，但没有明显的理由不在您的情况下使用默认设置。

我不知道为什么你认为Connection.Execute()不起作用，特别是因为你似乎有静态SQL：

Function FetchOneField(Connection, SQL)
  With Connection.Execute(SQL)
    FetchOneField = .Fields(0).Value
    .Close
  End With
End Function

SomeID    = FetchOneField(Connection, "SELECT SomeID FROM TableA")
AnotherID = FetchOneField(Connection, "SELECT AnotherID FROM TableB")

' or, not expressed as a function (not less lines, but "tidier" nevertheless)'
With Connection.Execute("SELECT SomeID FROM TableA")
  SomeID = .Fields(0).Value
  .Close
End With

Answer 2

假设每个查询有1条记录，你可以这样做

SQL = "SELECT TableA.SomeID, TableB.AnotherID FROM TableA, TableB"
RecordSet.Open SQL, Connection, adOpenStatic, adLockOptimistic, adCmdText
SomeID = RecordSet.Fields(0).Value
AnotherID = RecordSet.Fields(1).Value
RecordSet.Close

Answer 3

Connection.Execute 应该工作。这对我有用：

  Const Sql1 As String = "SELECT SomeID FROM TableA"
  SomeID = Connection.Execute(Sql1)(0).Value

  Const Sql2 As String = "SELECT AnotherID FROM TableB"
  AnotherID = Connection.Execute(Sql2)(0).Value

...虽然我亲自将Connection.Execute行封装在那些我可以明确表示从连接池中释放连接等的行中。

更优雅的解决方案，使用记录集从DB中提取价值

3 个答案: