How can I add a parameter for mysql variable? - mysql

Question

I have query in mysql which contains one variable. The query is
SELECT
GROUP_CONCAT(
CONCAT(
' MAX(IF(Property = ''',
t.Property,
''', Value, NULL)) AS ',
t.Property
)
) INTO #PivotQuery
FROM
(SELECT
Property
FROM
ProductOld
GROUP BY
Property) t;
SET #PivotQuery = CONCAT('SELECT ProductID,', #PivotQuery, ' FROM ProductOld GROUP BY ProductID');
PREPARE statement FROM #PivotQuery;
EXECUTE statement;
DEALLOCATE PREPARE statement;
But, when I run using mysqlcommand in my vb.net application, it throws an error stating that Parameter #PivotQuery must be defined..

Answer 1

Exchange This Code With your Existing Code:
SET #PivotQuery = CONCAT('SELECT ProductID',#PivotQuery,'FROM ProductOld GROUP BY ProductID');

Answer 2

Private Function saveCustomer()
Dim command As MySqlCommand = Nothing
Dim query As String = "INSERT INTO contacts (first_name, surname, house_number, street, suburb, state, phone, mobile, work, email, notes) VALUES (#first_name, #surname, #housenumber, #street, #suburb, #state, #phone, #mobile, #work, #email, #notes)"
Try
If connection.State = ConnectionState.Closed Then
connection.Open()
End If
command = New MySqlCommand(query, connection)
command.Parameters.AddWithValue("#first_name", txtFirstName.Text)
command.Parameters.AddWithValue("#surname", txtSurname.Text)
command.Parameters.AddWithValue("#housenumber", txtHouseNo.Text)
command.Parameters.AddWithValue("#street", txtStreet.Text)
command.Parameters.AddWithValue("#suburb", txtSuburb.Text)
command.Parameters.AddWithValue("#state", cboState.Text)
command.Parameters.AddWithValue("#phone", txtPhone.Text)
command.Parameters.AddWithValue("#mobile", txtMobile.Text)
command.Parameters.AddWithValue("#work", txtWork.Text)
command.Parameters.AddWithValue("#email", txtEmail.Text)
command.Parameters.AddWithValue("#notes", txtNotes.Text)
command.ExecuteNonQuery()
MessageBox.Show("Contact Saved Sucessfully")
Return True
Catch ex As MySqlException
Return False
Finally
connection.Close()
command.Dispose()
End Try