VS2010 MySqlException was unhandled - mysql

Question

I am new to VB programming and have come across an problem:( after a couple of days trying to resolve this need some help!
I am trying to pass some information from a VB form to my MySQL database. i have named all the textbox's the same as the field in the database and checked all my database fields and textbox names which are all correct.
When i try to enter information into a form I sometimes get an error at the .executeNonQuery section of the code.
To test, I outputted the SQLStatement string to a textbox ( which pulled through all the fields from the textboxes correctly) then manually inputted the completed SQL query into the database and it worked. But when I try to do this in one go it seems to fail if there is too much text ( if i enter 'a' into each field it works). Are they limits to the size of the SQL query that can be passed from VB?? all the MySql database fields are set to text with no size limits.
Thanks in advance!!!
Public Sub SaveQuote(ByRef SQLStatement As String)
Dim cmd As MySqlCommand = New MySqlCommand
With cmd
.CommandText = SQLStatement
.CommandType = CommandType.Text
.Connection = SQLConnection
.ExecuteNonQuery()
End With
SQLConnection.Close()
MsgBox("successfully Added!")
SQLConnection.Dispose()
End Sub
Private Sub CmdSave_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CmdSave.Click
Dim SQLstatement As String = "INSERT INTO laptopstock(forename,surname,emailaddress,contactnumber,quotedate,manufacturer,model,os,battery,drive,defects) VALUES('" & forename.Text & "','" & surname.Text & "','" & emailaddress.Text & "','" & contactnumber.Text & "', CURDATE(),'" & manufacturer.Text & "','" & modelnumber.Text & "','" & os.Text & "','" & batterycondition.Text & "','" & drivetype.Text & "','" & defects.Text & "')"
SaveQuote(SQLstatement)
End Sub
'Test SQL query
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim testSQLstatement As String = "INSERT INTO laptopstock(forename,surname,emailaddress,contactnumber,quotedate,manufacturer,model,os,battery,drive,defects) VALUES('" & forename.Text & "','" & surname.Text & "','" & emailaddress.Text & "','" & contactnumber.Text & "', CURDATE(),'" & manufacturer.Text & "','" & modelnumber.Text & "','" & os.Text & "','" & batterycondition.Text & "','" & drivetype.Text & "','" & defects.Text & "')"
testbox.Text = testSQLstatement
End Sub
here is the output from testSQLstatement = testbox.text
INSERT INTO laptopstock(forename,surname,emailaddress,contactnumber,quotedate,manufacturer,model,os,battery,drive,defects) VALUES('Joe','Bloggs','J.bloggs#jbloggs.com','07777777777', CURDATE(),'Sony','Vaio','Windows 7 Pro','Poor','DVD-Rom','Faulty Screen')
from what i can see it is correctly formatted and when i enter this directly into a query on the MySql server a record is created

Answer 1

Does your application SQL login have insert rights on this table? Try executing a grant statment in SQL console directly:
"grant insert on dbo.laptopstock to (add you application login here)"
Also, I why are you passing the SQLStatement byref? You are not modifying it, so use byval. This shouldn't impact the code, but is a good practice.
I see you state that sometimes you get an error, so we can asume it is working code. That leads me to believe it is in your input data. Do the fields accept nulls? Are they the right format? Also, one of these things is not like the others, the date. You are passing the curdate() function in the insert. If the fields are all strings like you mention, then you are performing an implicit conversion from date to string. You could as easily built the insert string using the Vb.Net equivalent. (Date.Now.ToString).
Lastly, it is hard to debug this without more detailed information about the
error. As you have not posted code for your SQLConnection and MySLCommand objects (sure you don't mean MySQLCommand as New SQLCommand) I have to assume they work.