select columns with not null property - mysql

Question

I am looking for a way to select columns with a not null property and store it on to an ArrayList.
I have searched many threads for an answer but no luck.
I created a function which allows me to read data from a table but the problem is I don't know how do I get it to read the column name with a not null property. Here is the code that I tried
Public Function getNull(ByVal table As String) As ArrayList
Dim col_names As String = New String(getNames(table))
Dim nullColumns As ArrayList = New ArrayList
Dim dtreader As MySqlDataReader
Dim conn As MySqlConnection
Dim strConn As String
strConn = withDatabase
conn = New MySqlConnection(strConn)
Try
Dim cmd = New MySqlCommand("SELECT * FROM " & table & " WHERE " & col_names & " IS NOT NULL", conn)
conn.Open()
dtreader = cmd.ExecuteReader()
While dtreader.Read
'Get column names with not null property'
End While
Catch ex As Exception
MsgBox("Error " + ex.ToString, MsgBoxStyle.Critical)
End Try
Return nullColumns
End Function
Public Function getNames(ByVal table As String) As String
Dim conn As MySqlConnection
Dim strConn As String
Dim names As New String("")
strConn = withDatabase
conn = New MySqlConnection(strConn)
Using conn
conn.Open()
Dim dt = conn.GetSchema("Columns", New String() {Nothing, Nothing, table})
For Each row In dt.Rows
names += row("COLUMN_NAME") + " AND "
Next
names = names.Remove(names.Length - 4)
End Using
conn.Close()
Return names
End Function
The other threads I found was to find null values in a column, which is not I was looking for.