Cannot update Data in mySQL database - mysql

Question

What I want to do is, check first if the ID number exist, then if it exist then do the updating process, but the problem is, it does not update. What is the problem ?
sqlconn = New MySqlConnection
sqlconn.ConnectionString = "server=localhost;userid=root;password='';database=innovative"
Try
sqlconn.Open()
query = "SELECT Full_Name FROM employee WHERE ID='" & txt_id_number.Text & "'"
cmd = New MySqlCommand(query, sqlconn)
reader = cmd.ExecuteReader
If reader.HasRows = False Then
MsgBox("Invalid ID number please secure that the ID number is already Exist" & vbNewLine & "TAKE NOTE:" & vbNewLine & "You cannot update or change the existing ID number for it is the primary Key for the Employee, If you want to Change it, its better to delete the Employee then add it again." & vbNewLine & "Other than that you can change the Full name, age, contact and etc.", vbCritical)
Else
reader.Close()
sqlconn.Open()
query1 = "UPDATE employee SET Full_Name ='" & txt_fullname.Text & "', Employee_Type='" & txt_employee_type.Text & "', Age='" & txt_age.Text & "',Sex='" & cb_sex.Text & "', Status='" & txt_status.Text & "', Contact ='" & txt_contact.Text & "',E_mail='" & txt_email.Text & "' WHERE ID = '" & txt_id_number.Text & "'"
cmd = New MySqlCommand(query1, sqlconn)
reader1 = cmd.ExecuteReader
MsgBox(txt_fullname.Text & " was successfully updated", vbInformation)
txt_age.Text = ""
txt_contact.Text = ""
txt_email.Text = ""
txt_employee_type.Text = ""
txt_fullname.Text = ""
txt_id_number.Text = ""
txt_status.Text = ""
cb_sex.Text = ""
add_employee()
End If
sqlconn.Close()
Catch ex As Exception
Finally
sqlconn.Dispose()
End Try

Answer 1

Imports MySql.Data.MySqlClient
Public Class Form1
Private sqlconn As MySqlConnection
Private query, query1 As String
Private cmd As MySqlCommand
Private reader As MySqlDataReader
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
sqlconn = New MySqlConnection
sqlconn.ConnectionString = "server=localhost;userid=root;password='';database=innovative"
Try
sqlconn.Open()
query = "SELECT Full_Name FROM employee WHERE ID='" & txt_id_number.Text & "'"
cmd = New MySqlCommand(query, sqlconn)
reader = cmd.ExecuteReader
If reader.HasRows = False Then
MsgBox("Invalid ID number please secure that the ID number is already Exist" & vbNewLine & "TAKE NOTE:" & vbNewLine & "You cannot update or change the existing ID number for it is the primary Key for the Employee, If you want to Change it, its better to delete the Employee then add it again." & vbNewLine & "Other than that you can change the Full name, age, contact and etc.", vbCritical)
Else
query1 = "UPDATE employee SET Full_Name = #txt_fullname, Employee_Type=txt_employee_type, Age=#txt_age'"
cmd = New MySqlCommand(query1, sqlconn)
cmd.CommandType = CommandType.Text
cmd.Parameters.Add("#txt_fullname", SqlDbType.VarChar, 255).Value = txt_fullname.Text
cmd.Parameters.Add("#txt_employee_type", SqlDbType.VarChar, 255).Value = txt_employee_type.Text
cmd.Parameters.Add("#txt_age", SqlDbType.VarChar, 255).Value = txt_age.Text
cmd.Parameters.Add("")
cmd.ExecuteNonQuery()
MsgBox(txt_fullname.Text & " was successfully updated", vbInformation)
txt_age.Text = ""
txt_contact.Text = ""
txt_email.Text = ""
txt_employee_type.Text = ""
txt_fullname.Text = ""
txt_id_number.Text = ""
txt_status.Text = ""
cb_sex.Text = ""
add_employee()
End If
sqlconn.Close()
reader.Close()
Catch ex As Exception
Finally
sqlconn.Dispose()
End Try
End Sub
End Class

Answer 2

Three things to change.
Use cmd.ExecuteNonQuery for Insert or Update queries.
Do not use conn.Open again when it is not closed; It returns 'Connection is already open' error and execution will terminate to catch block. This is the reason why your code didnt work.
Parameterize the queries for security and type-casting.
Happy coding!