> Harshan wrote: > I think it would be more in designing databases rather than writing sqls. Designing databases = (for a large part) designing constraints Desiging constraints = writing SQL assertions Writing SQL assertions = writing SQL queries. You benefit in both areas. Really you do. -- +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+- Toon Koppelaars RuleGen BV +31-615907269 toon_at_rulegen_dot_com www_dot_rulegen_dot_com *Author: "Applied Mathematics for Database Professionals"*