odbc sql php

This question is more on odbc sql than on php, since I'm sure everthing is working on php side I have a php form who fills on ODBC database ( Visual Foxpro) , everthing is working except with one detail, I have a text area field on my form and when the user fill this area with to many characters the sql query isn't accepted, I found that the problem is due to the length of the data. The field is a memo field who means they can accept any length, This works ok UPDATE catalogo SET MATERIAL = 'A12' WHERE KEYUNICA = 3941 But this crash UPDATE catalogo SET MATERIAL = 'A123456789B123456789C123456789D123456789E123456789F123456789G123456789H1234 56789I123456789J123456789K123456789L123456789M123456789N123456789O123456789P 123456789q123456789r123456789s123456789t123456789u123456789v123456789x123456 789y123456789z123456789a123456789b123456789' WHERE KEYUNICA = 3941 The question is How is the write way to write a query when I need to updated a field of type memo with information from a Textarea or even any big array of letters ? Any tip ?