Question

我有一个代码，用于从select SQL语句创建数据表（在内存中）。但是我意识到这个数据表在程序期间填充而不是作为事务comit语句的结果，它完成了工作，但速度很慢。我做错了什么？

 Inalready.Clear() 'clears a dictionary
        Using connection As New SQLite.SQLiteConnection(conectionString)
            connection.Open()
            Dim sqliteTran As SQLite.SQLiteTransaction = connection.BeginTransaction()
            Try
                oMainQueryR = "SELECT * FROM detailstable  Where name= :name AND Breed= :Breed"
                Dim cmdSQLite As SQLite.SQLiteCommand = connection.CreateCommand()

                Dim oAdapter As New SQLite.SQLiteDataAdapter(cmdSQLite)

                With cmdSQLite
                    .CommandType = CommandType.Text
                    .CommandText = oMainQueryR
                    .Parameters.Add(":name", SqlDbType.VarChar)
                    .Parameters.Add(":Breed", SqlDbType.VarChar)
                End With

                Dim c As Long = 0
                For Each row As DataRow In list.Rows 'this is the list with 500 names

                    If Inalready.ContainsKey(row.Item("name")) Then
                    Else
                        c = c + 1
                        Form1.TextBox1.Text = " Fill .... " & c
                        Application.DoEvents()

                        Inalready.Add(row.Item("name"), row.Item("Breed"))

                        cmdSQLite.Parameters(":name").Value = row.Item("name")
                        cmdSQLite.Parameters(":Breed").Value = row.Item("Breed")
                        oAdapter.Fill(newdetailstable)
                    End If

                Next

                oAdapter.FillSchema(newdetailstable, SchemaType.Source)


                Dim z = newdetailstable.Rows.Count

'此时newdetailstable已经填满，我甚至没有提交交易

                '  sqliteTran.Commit()

            Catch ex As Exception
            End Try
        End Using

Answer 1

交易防止其他用户（即连接）所做的更改;您自己的应用程序所做的任何更改都会立即显示出来。

因此，对于内存数据库，除非您需要回滚，否则事务无用。

SQLite Transaction在提交事务之前填充表

1 个答案: