After adding to hosted mysql base how to read vbasic 2012 - mysql

Question

I'm working on simple project to figure out how databases work.
I created mysql base on my host and used this code to connect to it
Private mysql_host = "myhost"
Private mysql_user = "myuser"
Private mysql_pass = "mypw"
Private mysql_db = "mydb"
Private SQLConnect As String = "Server=" + mysql_host + ";" + "User Id=" + mysql_user + ";" + "Password=" + mysql_pass + ";" + "Database=" + mysql_db
Private SQLConnection As New MySqlConnection
Private Sub Form1_Load(sender As Object, e As System.EventArgs) Handles Me.Load
sqlConnection.ConnectionString = SQLConnect
Try
If sqlConnection.State = ConnectionState.Closed Then
sqlConnection.Open()
MsgBox("Connected")
Else
sqlConnection.Close()
MsgBox("Not Connected")
End If
Catch ex As Exception
MsgBox(ex.ToString)
End Try
End Sub
After that i used this code to add record into database.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim SQLStatement As String = "INSERT into tCodes(Code) VALUES ('" & TextBox1.Text & "')"
Dim cmd As New MySqlCommand
With cmd
.CommandText = SQLStatement
.CommandType = CommandType.Text
.Connection = SQLConnection
.ExecuteNonQuery()
End With
MsgBox("Added")
End Sub
On the other form i want to check if record exist in database. How to do that .
I tried with code
Dim SQLStatement As String = "SELECT * From tCodes WHERE Code '" & TextBox1.Text & "'")

Answer 1

For read . Me using this
Private host As String = "host" 'Host DB
Private user As String = "user" 'User DB
Private pass As String = "pass" 'Pass DB
Private base As String = "base" 'Base
Private conn As String = "Database=" & base & ";Data Source=" & host & ";User Id=" & _
user & ";Password=" & pass 'Connection
Private Connection As New MySqlConnection(conn) 'Connection
Private readData As MySqlDataReader 'Data Reader
Private adaptsData As New MySqlDataAdapter 'Data Adapter
Private command As New MySqlCommand 'command
Private ds As New DataSet 'DataSet
After
Public Function __select(Optinal table as String = "tCodes") As String
Try
Connection.Open()
Dim query As String = "SELECT * FROM " & table
command.CommandText = query
command.Connection = conexiune
adaptsData.SelectCommand = comanda
adaptsData.Fill(ds, tabla)
Dim newvalue As String = ds.Tables(tabla).Rows(0).Item(item)
ds.Dispose()
ds.Clear()
Connection.Close()
Return newvalue
Catch ex As Exception
ds.Dispose()
ds.Clear()
conexiune.Close()
msgbox(ex.message)
End Try
End Function

Answer 2

Dim conn As MySqlConnection
Dim sqlquery = "SELECT * FROM tCodes WHERE Code = '" + txtCode.Text + "'"
Dim myCommand As New MySqlCommand()
myCommand.Connection = conn
myCommand.CommandText = sqlquery
'start query
myAdapter.SelectCommand = myCommand
Dim myData As MySqlDataReader
myData = myCommand.ExecuteReader()
'see if user exists
If myData.HasRows = 0 Then
MsgBox("Kod je nevazeci")
conn.Close()
Else
MsgBox("Kod je vazeci")
End If
That was the solution of this problem