The OCLOperator PSEval makes it possible to use oclPS in any OCL expression. Using this, you can "reach into" the database from OCL and action-language (EAL).

Expression template:

SomeClass.PSEval(<ps-expression>,maxfetch,offset,<dependon>)

Note! PSEval doesn't subscribe to sets from DB. To make the operator auto-updating, provide an expression in "dependon" that, when changed, should also rerun the PSEval expression. This can, for example, be a timer.

Example:

Uppdrag.PSEval(self.Uppdrag->select(u|u.Aktivt)->orderDescending(u|u.Startdatum),  1000, 0, self.Uppdrag)

For example, this expression from a method has "userName" as a parameter:

SysUser.PSEval(SysUser.allinstances->select(su|su.Username=userName),2,0,'')

Always remember that your SQL-server might also need indexes and other performance settings to execute your expression efficiently.

See also: Sqlpassthrough, PSEvalValue, PSEvalTuples