Construct, Q+E, QBE

I'm migrating my code from Informix 4GL to PHP, my problem now is how to give the users the ability to make a query with the facilities that the CONTRUCT verb gives in 4GL. Suppose a form field name 'price' where the users can type the search criteria If the user type ... I need to get ... 123.23 "price = 123.23" >100 "price > 100" <=500 "price <= 500" 100..200 "price between 100 and 200" 100,200 "price in (100,200)" In a string field named "city" If the user type ... I need to get sacramento "city = 'SACRAMENTO'" sacra* "city MATCHES 'SACRA*'" >Wy "city > 'WY" etc. Something like .. $qbe = qbe('city','options') $qry = "select * from customers where ".$qbe; and the qbe function can get the typed from $_POST[$parm1] and using the options chose between char or numeric data type , upshift or as is, matches or like, etc. Exist something like that? I'm reinventing the wheel? How are you solving this kind of problem? TIA -- Fernando Ortiz Muñoz Fabrica de Jabon la Corona, SA de CV MEXICO