根据OracleDataAdapter Class：

线程安全

所有公共静态方法都是线程安全的，尽管实例方法 不保证线程安全。

对于连接，建议只在需要时才打开连接。如果一个连接持续被使用，保持它打开可能是有意义的。否则，每次都打开/关闭连接。当然，如果您有其他需要使用连接执行的操作，您可以将连接作为参数传递给方法。但是，请在完成操作后关闭连接。

以下假设已安装 NuGet 包 Oracle.ManagedDataAccess。

尝试以下操作之一：

Imports Oracle.ManagedDataAccess.Client

Public Module Helper

    Public Function FetchDataDS(connectionStr As String,str_SQL As String) As DataSet
        Dim int_Count As Integer = 0
        Dim ds As DataSet = New DataSet()

        Using connection As OracleConnection = New OracleConnection(connectionStr)
            'open
            connection.Open()

            Using oracleDataAdapter As OracleDataAdapter = New OracleDataAdapter With {
                .SelectCommand = New OracleCommand With {
                        .AddToStatementCache = False,.NotificationAutoEnlist = False,.CommandTimeout = 60,.Connection = connection,.CommandText = str_SQL
                    }}

                int_Count = oracleDataAdapter.Fill(ds)
            End Using
        End Using

        Return ds
    End Function

    Public Function FetchDataDS(connection As OracleConnection,str_SQL As String) As DataSet
        Dim int_Count As Integer = 0
        Dim ds As DataSet = New DataSet()

        If connection.State = ConnectionState.Closed Then
            'open
            connection.Open()
        End If

        If Not connection.State = ConnectionState.Open Then
            Throw New Exception("Error (FetchDataDS) - Connection state is: " & connection.State.ToString())
        End If

        Using oracleDataAdapter As OracleDataAdapter = New OracleDataAdapter With {
                .SelectCommand = New OracleCommand With {
                        .AddToStatementCache = False,.CommandText = str_SQL
                    }}

            int_Count = oracleDataAdapter.Fill(ds)
        End Using

        Return ds
    End Function

    Public Function FetchDataDS(connectionStr As String,str_SQL As String,ds As DataSet) As Integer
        Dim int_Count As Integer = 0

        Using connection As OracleConnection = New OracleConnection(connectionStr)
            'open
            connection.Open()

            Using oracleDataAdapter As OracleDataAdapter = New OracleDataAdapter With {
                .SelectCommand = New OracleCommand With {
                        .AddToStatementCache = False,.CommandText = str_SQL
                    }}

                int_Count = oracleDataAdapter.Fill(ds)
            End Using
        End Using

        Return int_Count
    End Function

    Public Function FetchDataDS(connection As OracleConnection,ds As DataSet) As Integer
        Dim int_Count As Integer = 0

        If connection.State = ConnectionState.Closed Then
            'open
            connection.Open()
        End If

        If Not connection.State = ConnectionState.Open Then
            Throw New Exception("Error (FetchDataDS) - Connection state is: " & connection.State.ToString())
        End If

        Using oracleDataAdapter As OracleDataAdapter = New OracleDataAdapter With {
                .SelectCommand = New OracleCommand With {
                        .AddToStatementCache = False,.CommandText = str_SQL
                    }}

            int_Count = oracleDataAdapter.Fill(ds)
        End Using

        Return int_Count
    End Function

    Public Function FetchDataDT(connectionStr As String,str_SQL As String) As DataTable
        Dim int_Count As Integer = 0
        Dim dt As DataTable = New DataTable()

        Using connection As OracleConnection = New OracleConnection(connectionStr)
            'open
            connection.Open()

            Using oracleDataAdapter As OracleDataAdapter = New OracleDataAdapter With {
                .SelectCommand = New OracleCommand With {
                        .AddToStatementCache = False,.CommandText = str_SQL
                    }}

                int_Count = oracleDataAdapter.Fill(dt)
            End Using
        End Using

        Return dt
    End Function

    Public Function FetchDataDT(connection As OracleConnection,str_SQL As String) As DataTable
        Dim int_Count As Integer = 0
        Dim dt As DataTable = New DataTable()

        If connection.State = ConnectionState.Closed Then
            'open
            connection.Open()
        End If

        If Not connection.State = ConnectionState.Open Then
            Throw New Exception("Error (FetchDataDT) - Connection state is: " & connection.State.ToString())
        End If

        Using oracleDataAdapter As OracleDataAdapter = New OracleDataAdapter With {
                .SelectCommand = New OracleCommand With {
                        .AddToStatementCache = False,.CommandText = str_SQL
                    }}

            int_Count = oracleDataAdapter.Fill(dt)
        End Using

        Return dt
    End Function

    Public Function FetchDataDT(connection As OracleConnection,dt As DataTable) As Integer
        Dim int_Count As Integer = 0

        If connection.State = ConnectionState.Closed Then
            'open
            connection.Open()
        End If

        If Not connection.State = ConnectionState.Open Then
            Throw New Exception("Error (FetchDataDT) - Connection state is: " & connection.State.ToString())
        End If

        Using oracleDataAdapter As OracleDataAdapter = New OracleDataAdapter With {
                .SelectCommand = New OracleCommand With {
                        .AddToStatementCache = False,.CommandText = str_SQL
                    }}

            int_Count = oracleDataAdapter.Fill(dt)
        End Using

        Return int_Count
    End Function
End Module

无论在哪里捕获异常，也要捕获 Oracle.ManagedDataAccess.Client.OracleException -

类似于以下内容：

Try
    'ToDo: add desired code
       ...
Catch ex As OracleException
    'ToDo: log exception
Catch ex As Exception
    'ToDo: log exception
End Try

资源

• OracleCommand Properties
• CommandTimeout
• Timeout of OracleDataAdapter.Fill() [duplicate]
• Module Statement
• Access Levels in Visual Basic