Inserting data into a MySQL table using VB.NET - mysql

Question

I have a problem inserting data into a table on a MySQL database using a VB.NET application.
I have a simple form where when I set some data to the textboxes and I press a GO button, the code should execute a function called InsertCar() that takes all these values and insert them into the database and then return true if the transaction is done successfully or false otherwise. My problem is that nothing is being inserted into the table.
Imports MySql.Data.MySqlClient
Imports System.Data.Sql
Imports System
Imports System.Data
Public Class Form1
Dim connectionString As String = "Server=localhost; User Id=root; Password=123456; Database=uni_park_db"
Dim SQLConnection As MySqlConnection = New MySqlConnection
Dim oDt_sched As New DataTable()
//SOME CODE For other buttons//
//Code for a button where the InsertCar() function is called at the beginning//
Public Function InsertCar() As Boolean
SQLConnection = New MySqlConnection()
SQLConnection.ConnectionString = connectionString
Dim sqlCommand As New MySqlCommand
Dim str_carSql As String
Try
str_carSql = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values ('" + TextBox20.Text + "','" + TextBox20.Text + "','" + TextBox23.Text + "','" + TextBox24.Text + "','" + TextBox22.Text + "','" + TextBox21.Text + "','" + ComboBox1.SelectedItem + "')"
MsgBox(str_carSql)
sqlCommand.Connection = SQLConnection
sqlCommand.CommandText = str_carSql
sqlCommand.ExecuteNonQuery()
Return True
Catch ex As Exception
Return False
MsgBox("Error occured: Could not insert record")
End Try
End Function
End Class
I am using this MsgBox(str_carSql) to test if the SQL statement is correct and it is correct.
Any help will be appreciated.
UPDATE
I did the following and it stills not working
Public Function InsertCar() As Boolean
SQLConnection = New MySqlConnection()
SQLConnection.ConnectionString = connectionString
SQLConnection.Open()
Dim sqlCommand As New MySqlCommand
Dim str_carSql As String
Try
str_carSql = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values (#id,#m_id,#model,#color,#ch_id,#pt_num,#code)"
sqlCommand.Connection = SQLConnection
sqlCommand.CommandText = str_carSql
sqlCommand.Parameters.AddWithValue("#id", TextBox20.Text)
sqlCommand.Parameters.AddWithValue("#m_id", TextBox20.Text)
sqlCommand.Parameters.AddWithValue("#model", TextBox23.Text)
sqlCommand.Parameters.AddWithValue("#color", TextBox24.Text)
sqlCommand.Parameters.AddWithValue("#ch_id", TextBox22.Text)
sqlCommand.Parameters.AddWithValue("#pt_num", TextBox21.Text)
sqlCommand.Parameters.AddWithValue("#code", ComboBox1.SelectedItem)
sqlCommand.ExecuteNonQuery()
Return True
Catch ex As Exception
Return False
MsgBox("Error occured: Could not insert record")
End Try
End Function
UPDATE
The Insert is not working either, I will post the entire code maybe a problem is found elsewhere
Imports MySql.Data.MySqlClient
Imports System.Data.Sql
Imports System
Imports System.Data
Public Class Form1
Dim connectionString As String = "Server=localhost; User Id=root; Password=123456; Database=uni_park_db"
Dim SQLConnection As MySqlConnection = New MySqlConnection
Dim oDt_sched As New DataTable()
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Try
If SQLConnection.State = ConnectionState.Open Then
If TextBox1.Text = "" Then
MsgBox("Please Input a Valid ID")
Else
Dim myAdapter1 As New MySqlDataAdapter("select m.work_date as Work, m.time_in as Start, m.time_out as End from university_members as u inner join members_schedule as m on u.members_schedule_id=m.members_schedule_id where member_id = " & TextBox1.Text, SQLConnection)
Dim myAdapter As New MySqlDataAdapter("select member_id, first_name, last_name, type from university_members, members_schedule where(university_members.members_schedule_id = members_schedule.members_schedule_id) AND member_id = " & TextBox1.Text, SQLConnection)
Dim mydatatable As New DataTable()
Dim dataset As New DataSet()
myAdapter.Fill(mydatatable)
If (mydatatable.Rows.Count > 0 And myAdapter1.Fill(dataset)) Then
TextBox2.Text = mydatatable.Rows(0).Item("first_name")
TextBox3.Text = mydatatable.Rows(0).Item("last_name")
TextBox4.Text = mydatatable.Rows(0).Item("type")
TextBox20.Text = mydatatable.Rows(0).Item("member_id")
DataGridView1.DataSource = dataset.Tables(0)
oDt_sched = dataset.Tables(0)
Else
MsgBox("Check Error: ID Not Found! Enter a Valid ID")
TextBox1.Text = "Example 123456 "
TextBox2.Text = " "
TextBox3.Text = " "
TextBox4.Text = " "
End If
End If
Else
MsgBox("Database Connection Error: Database Connection Not Established. Please Connect First.")
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub ExitToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ExitToolStripMenuItem.Click
Application.Exit()
End Sub
Private Sub DatabaseConnectToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles DatabaseConnectToolStripMenuItem.Click
SQLConnection = New MySqlConnection()
SQLConnection.ConnectionString = connectionString
Try
If SQLConnection.State = ConnectionState.Closed Then
SQLConnection.Open()
MsgBox("Database Connection Sccessfully Established")
Else
SQLConnection.Close()
MsgBox("Database Connection Terminated")
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
TextBox1.Text = "Example 123456 "
TextBox2.Text = " "
TextBox3.Text = " "
TextBox4.Text = " "
DataGridView1.Columns.Clear()
DataGridView1.DataSource = Nothing
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim str_sql As String = ""
Dim obj_msadapter As MySqlDataAdapter
Dim i_maxh As Integer
Dim i_beginh As Integer
Dim ods_avail As DataSet = New DataSet()
Dim str_err As String = ""
Dim i_strth As Integer
Dim odt_avail As New DataTable()
Dim odrcol_avail() As DataRow
Dim str_range As String = ""
Try
'perform insert car here (boolean to see if the code continues running)
''''''''''''''''''''''''''
If InsertCar() Then
For Each odr As DataRow In oDt_sched.Rows
i_maxh = odr(2)
i_beginh = odr(1)
i_strth = odr(1) + 2
str_range = ""
str_sql = "select * from parked_cars where pwork_date='" & odr(0).ToString() & "'"
ods_avail = New DataSet()
obj_msadapter = New MySqlDataAdapter(str_sql, SQLConnection)
obj_msadapter.Fill(ods_avail)
odt_avail = ods_avail.Tables(0)
If odt_avail.Rows.Count < 210 Then
While (i_strth <= i_maxh)
odrcol_avail = odt_avail.Select("ptime_in='" + i_beginh.ToString() + "' and ptime_out='" + i_strth.ToString() + "'")
If odrcol_avail.Count < 30 Then
str_range += i_beginh.ToString() + ";" + i_strth.ToString()
Else
str_range += "0"
End If
i_strth += 2
i_beginh += 2
End While
FillSpots(str_range, odr(0).ToString())
Else
str_err += "no place on day: " + odr(0).ToString() + ";"
MsgBox("No place is found on this day")
End If
Next
End If
Catch ex As Exception
MsgBox("")
End Try
End Sub
Public Function FillSpots(ByVal blowf As String, ByVal _day As String) As Boolean
Dim str_unit As String
Dim i_count As Integer = 0
Dim str_i_strt As String
Dim str_i_end As String
Dim str_sql As String
Try
For Each str_unit In blowf.Split("0")
If str_unit <> "" Then
str_i_strt = str_unit.Split(";")(0)
str_i_end = str_unit.Split(";")(str_unit.Split(";").Length - 1)
str_sql = "insert into parked_cars values ('" + TextBox20.Text + "','" + _day + "','" + str_i_strt + "','" + str_i_end + "')"
End If
Next
Return True
Catch ex As Exception
Throw ex
End Try
End Function
Public Function InsertCar() As Boolean
SQLConnection = New MySqlConnection()
SQLConnection.ConnectionString = connectionString
SQLConnection.Open()
Dim sqlCommand As New MySqlCommand
Dim str_carSql As String
Try
str_carSql = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values (?id,?m_id,?model,?color,?ch_id,?pt_num,?code)"
sqlCommand.Connection = SQLConnection
sqlCommand.CommandText = str_carSql
sqlCommand.CommandType = CommandType.Text
sqlCommand.Parameters.AddWithValue("?id", TextBox20.Text)
sqlCommand.Parameters.AddWithValue("?m_id", TextBox20.Text)
sqlCommand.Parameters.AddWithValue("?model", TextBox23.Text)
sqlCommand.Parameters.AddWithValue("?color", TextBox24.Text)
sqlCommand.Parameters.AddWithValue("?ch_id", TextBox22.Text)
sqlCommand.Parameters.AddWithValue("?pt_num", TextBox21.Text)
sqlCommand.Parameters.AddWithValue("?code", ComboBox1.SelectedItem)
sqlCommand.ExecuteNonQuery()
Return True
Catch ex As Exception
Return False
MsgBox("Error occured: Could not insert record")
End Try
End Function
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
ComboBox1.ResetText()
TextBox21.Text = " "
TextBox22.Text = " "
TextBox23.Text = " "
TextBox24.Text = " "
DataGridView2.Columns.Clear()
DataGridView2.DataSource = Nothing
End Sub
End Class
Thanks everyone for the help. This is the solution that worked for me
Dim iReturn as boolean
Using SQLConnection As New MySqlConnection(connectionString)
Using sqlCommand As New MySqlCommand()
With sqlCommand
.CommandText = "INSERT INTO members_car (`car_id`, `member_id`, `model`, `color`, `chassis_id`, `plate_number`, `code`) values (#xid,#m_id,#imodel,#icolor,#ch_id,#pt_num,#icode)"
.Connection = SQLConnection
.CommandType = CommandType.Text // You missed this line
.Parameters.AddWithValue("#xid", TextBox20.Text)
.Parameters.AddWithValue("#m_id", TextBox20.Text)
.Parameters.AddWithValue("#imodel", TextBox23.Text)
.Parameters.AddWithValue("#icolor", TextBox24.Text)
.Parameters.AddWithValue("#ch_id", TextBox22.Text)
.Parameters.AddWithValue("#pt_num", TextBox21.Text)
.Parameters.AddWithValue("#icode", ComboBox1.SelectedItem)
End With
Try
SQLConnection.Open()
sqlCommand.ExecuteNonQuery()
iReturn = TRUE
Catch ex As MySqlException
MsgBox ex.Message.ToString
iReturn = False
Finally
SQLConnection.Close()
End Try
End Using
End Using
Return iReturn

Answer 1

After instantiating the connection, open it.
SQLConnection = New MySqlConnection()
SQLConnection.ConnectionString = connectionString
SQLConnection.Open()
Also, avoid building SQL statements by just appending strings. It's better if you use parameters, that way you win on performance, your program is not prone to SQL injection attacks and your program is more stable. For example:
str_carSql = "insert into members_car
(car_id, member_id, model, color, chassis_id, plate_number, code)
values
(#id,#m_id,#model,#color,#ch_id,#pt_num,#code)"
And then you do this:
sqlCommand.Parameters.AddWithValue("#id",TextBox20.Text)
sqlCommand.Parameters.AddWithValue("#m_id",TextBox23.Text)
' And so on...
Then you call:
sqlCommand.ExecuteNonQuery()

Answer 2

You need to open the connection first:
SQLConnection.Open();

Answer 3

Dim connString as String ="server=localhost;userid=root;password=123456;database=uni_park_db"
Dim conn as MySqlConnection(connString)
Dim cmd as MysqlCommand
Dim dt as New DataTable
Dim ireturn as Boolean
Private Sub Insert_Car()
Dim sql as String = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values (#car_id,#member_id,#model,#color,#chassis_id,#plate_number,#code)"
Dim cmd = new MySqlCommand(sql, conn)
cmd.Paramaters.AddwithValue("#car_id", txtCar.Text)
cmd.Paramaters.AddwithValue("#member_id", txtMember.Text)
cmd.Paramaters.AddwithValue("#model", txtModel.Text)
cmd.Paramaters.AddwithValue("#color", txtColor.Text)
cmd.Paramaters.AddwithValue("#chassis_id", txtChassis.Text)
cmd.Paramaters.AddwithValue("#plate_number", txtPlateNo.Text)
cmd.Paramaters.AddwithValue("#code", txtCode.Text)
Try
conn.Open()
If cmd.ExecuteNonQuery() > 0 Then
ireturn = True
End If
conn.Close()
Catch ex as Exception
ireturn = False
conn.Close()
End Try
Return ireturn
End Sub

Answer 4

your str_carSql should be exactly like this:
str_carSql = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values (#id,#m_id,#model,#color,#ch_id,#pt_num,#code)"
Good Luck

Answer 5

You need to use ?param instead of #param when performing queries to MySQL
str_carSql = "insert into members_car (car_id, member_id, model, color, chassis_id, plate_number, code) values (?id,?m_id,?model,?color,?ch_id,?pt_num,?code)"
sqlCommand.Connection = SQLConnection
sqlCommand.CommandText = str_carSql
sqlCommand.Parameters.AddWithValue("?id", TextBox20.Text)
sqlCommand.Parameters.AddWithValue("?m_id", TextBox20.Text)
sqlCommand.Parameters.AddWithValue("?model", TextBox23.Text)
sqlCommand.Parameters.AddWithValue("?color", TextBox24.Text)
sqlCommand.Parameters.AddWithValue("?ch_id", TextBox22.Text)
sqlCommand.Parameters.AddWithValue("?pt_num", TextBox21.Text)
sqlCommand.Parameters.AddWithValue("?code", ComboBox1.SelectedItem)
sqlCommand.ExecuteNonQuery()
Change the catch block to see the actual exception:
Catch ex As Exception
MsgBox(ex.Message)
Return False
End Try

Answer 6

First, You missed this one: sqlCommand.CommandType = CommandType.Text
Second, Your MySQL Parameter Declaration is wrong. It should be # and not ?
try this:
Public Function InsertCar() As Boolean
Dim iReturn as boolean
Using SQLConnection As New MySqlConnection(connectionString)
Using sqlCommand As New MySqlCommand()
With sqlCommand
.CommandText = "INSERT INTO members_car (`car_id`, `member_id`, `model`, `color`, `chassis_id`, `plate_number`, `code`) values (#xid,#m_id,#imodel,#icolor,#ch_id,#pt_num,#icode)"
.Connection = SQLConnection
.CommandType = CommandType.Text // You missed this line
.Parameters.AddWithValue("#xid", TextBox20.Text)
.Parameters.AddWithValue("#m_id", TextBox20.Text)
.Parameters.AddWithValue("#imodel", TextBox23.Text)
.Parameters.AddWithValue("#icolor", TextBox24.Text)
.Parameters.AddWithValue("#ch_id", TextBox22.Text)
.Parameters.AddWithValue("#pt_num", TextBox21.Text)
.Parameters.AddWithValue("#icode", ComboBox1.SelectedItem)
End With
Try
SQLConnection.Open()
sqlCommand.ExecuteNonQuery()
iReturn = TRUE
Catch ex As MySqlException
MsgBox ex.Message.ToString
iReturn = False
Finally
SQLConnection.Close()
End Try
End Using
End Using
Return iReturn
End Function