(PHP 4 <= 4.1.0, PECL dbplus >= 0.9)
dbplus_find — Set a constraint on a relation
   Places a constraint on the given relation.
  
Further calls to functions like dbplus_curr() or dbplus_next() will only return tuples matching the given constraints.
relationA relation opened by dbplus_open().
constraints
       Constraints are triplets of strings containing of a domain name,
       a comparison operator and a comparison value. The
       constraints parameter array may consist of
       a collection of string arrays, each of which contains a domain, an
       operator and a value, or of a single string array containing a
       multiple of three elements.
      
The comparison operator may be one of the following strings: '==', '>', '>=', '<', '<=', '!=', '~' for a regular expression match and 'BAND' or 'BOR' for bitwise operations.
tuple
This function is EXPERIMENTAL. The behaviour of this function, its name, and surrounding documentation may change without notice in a future release of PHP. This function should be used at your own risk.