Excel file creating is a part of subsystem, but it can to work absolutely apart,stored procedure got parameters, creates file Excel on database server.

Procedure parameters:
• Query text
• File path
• Query parameters list

The main parameter is a select statement with parameters(as bind variable, type, :P_CUSTOMER) and parameters name-importance-type themselves and else much what in the manner of XML. In select text it possible to use the special language, which covers all possibility of a trigger and a placeholders of Oracle*Reports and gives possibility to build select optimally , that there is, from experience I see that if user does not use layout and he needs Excel, all possible to set for minute moreover final select is got such that DBA remain complacent. And Excel file is got cultural, in colour, there is separate spredsheets, where appear select user parameters, headline, which has assigned the user in aliases of select fields.
Language commands:

• VAR CHAR | NUMBER ;
• EXPR ;
• BEFORE {PL/SQL block} ;
• AFTER {PL/SQL block} ;
• IIF_EXPR {boolean expression} {String if true} {String if false} ;
• IS_NOT_NULL {Bind variable} {String if Bind variable is not null} ;
• IS_NULL {Bind variable} {String if Bind variable is null} ;
• TITLE {Title};
• BOTTOM_SUM {Total bottom title} B C ...Z ;
• ROW_SUM {Total column title} B C D ... Z;