使用VB.Net将文本文件的内容导入MySQL

Question

Good day everyone. I am trying to create a program that will transfer all of the contents of a text file into a database. So far, my code works, but my code only inserts the first line of the text file into the database. What should I add to solve the problem? I am noob at programming sorry.

Public Class Form1

    Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Dim filename As String = "C:\Users\user\desktop\swipe.txt"
        Dim Query As String
        Dim data As String = System.IO.File.ReadAllText(filename)
        Dim Loc, _date, time, temp, id As String
        Loc = data.Substring(0, 3)
        _date = data.Substring(3, 8)
        time = data.Substring(11, 4)
        temp = data.Substring(15, 3)
        id = data.Substring(18, 3)
        Query = "INSERT INTO tbl_entrance_swipe VALUES ('" + Loc + "','" + _date + "','" + time + "','" + temp + "','" + id + "')"
        Dim con As MySqlConnection = New MySqlConnection("Data Source=localhost;Database=cph;User ID=root;Password=;")
        Try
            con.Open()
            Dim sql As MySqlCommand = New MySqlCommand(Query, con)
            sql.ExecuteNonQuery()
            MsgBox("Record is Successfully Inserted")
            con.Close()
        Catch ex As Exception
            con.Close()
            MsgBox("Record is not Inserted" + ex.Message)
        End Try
    End Sub
End Class

Answer 1

You are using File.ReadAllText which reads the complete text of the file. You want to read line by line, therefore you can use File.ReadLines (deferred executed) or File.ReadAllLines (reads all into a String() ).

You should also use sql-parameters to prevent sql-injection and incorrect implicit type conversions or localization issues. Finally, use the Using statement to ensure that all unmanaged resources are disposed (fe the connection gets closed even on error):

Dim filename As String = "C:\Users\user\desktop\swipe.txt"
Dim allLines As String() = File.ReadAllLines(filename)
Dim query As String = "INSERT INTO tbl_entrance_swipe VALUES (@Loc, @Date, @Time, @Temp, @Id)"

Using con As MySqlConnection = New MySqlConnection("Data Source=localhost;Database=cph;User ID=root;Password=;")
    con.Open()
    Using cmd As New MySql.Data.MySqlClient.MySqlCommand(query, con)
        For Each line In allLines
            Dim loc, dt, time, temp, id As String
            loc = line.Substring(0, 3)
            dt = line.Substring(3, 8)
            time = line.Substring(11, 4)
            temp = line.Substring(15, 3)
            id = line.Substring(18, 3)
            cmd.Parameters.Clear()
            Dim pLoc As New MySql.Data.MySqlClient.MySqlParameter("@Loc", MySqlDbType.VarChar)
            pLoc.Value = loc
            cmd.Parameters.Add(pLoc)
            Dim pDate As New MySql.Data.MySqlClient.MySqlParameter("@Date", MySqlDbType.VarChar)
            pDate.Value = dt
            cmd.Parameters.Add(pDate)
            Dim pTime As New MySql.Data.MySqlClient.MySqlParameter("@Time", MySqlDbType.VarChar)
            pTime.Value = time
            cmd.Parameters.Add(pTime)
            Dim pTemp As New MySql.Data.MySqlClient.MySqlParameter("@Temp", MySqlDbType.VarChar)
            pTemp.Value = temp
            cmd.Parameters.Add(pTemp)
            Dim pId As New MySql.Data.MySqlClient.MySqlParameter("@Id", MySqlDbType.VarChar)
            pId.Value = id
            cmd.Parameters.Add(pId)

            cmd.ExecuteNonQuery()
        Next
        MsgBox("All records were inserted successfully")
        con.Close()
    End Using
End Using