Re: Triggers In Informix?

sh5@ornl.gov (Steve Huff) wrote: > >Two questions from a novice Informix programmer: > > >1. Does Informix support the definition of database "triggers" to allow some >defined activity (e.g. "update") on a column or row to automatically fire off >some pre-defined code? If so, where can I find information about how to do >this? I need to recalculate the value in one table every time one of the >contributing values in another tables gets updated. > >2. Is there anyway that I can cause a SELECT statement to return every >nth row from the rows satisfying the WHERE clause, where n is a parameter I >specify at the time of SELECT? Or equally acceptable to return a random >sample of size n% from the rows satisfying the WHERE clause? > Try the following: SELECT ... FROM ... WHERE ... AND MOD(ROWID,n)=0 This is probably not very random, but it should give you a reasonably well distributed sample of every nth row. -- John H. Frantz Check out Power-4gl Alive in Iceland! http://www.strengur.is/~frantz/pow4gl.html