On Wed, May 16, 2012 at 10:21 AM, John Townsend <jtownsend@xxxxxxxxxxxxxxxxxxxx> wrote: > It appears that some developers (Davart) are by-passing the standard client > library, “libpq.dll”, and directly accessing the server using Delphi or FPC. > I am not sure of the advantage here. All libpq.dll functions can be called > from Delphi or FPC by simply using the following example pascal coding: > const > > LIBPQ_PATH = 'C:\PG\libpq.dll'; // or wherever > > type > > PGconn = Pointer; > PPGresult = Pointer; > > var > Conn: PGconn; > ResultSet: PPGresult; > > > function PQconnectdbParams(keywords, values: PChar; expand_dbname: integer): > PGconn; cdecl; > > external LIBPQ_PATH name 'PQconnectdbParams'; > > function PQconnectdb(conninfo: PChar): PGConn; cdecl; > > external LIBPQ_PATH name 'PQconnectdb'; > > function PQsetdbLogin(Host, Port, Options, Tty, Db, User, Passwd: PChar): > PGconn; cdecl; > > external LIBPQ_PATH name 'PQsetdbLogin'; > > There are translation programs like “h2pas” that will do most of the work > for you, seeing that you may have to translate 160+ c functions. > Nonetheless, it shouldn’t take long, and one would have a nice module, > (unit) to use for building a PostgreSQL database application using Delphi or > FPC. Using the module one could build components as many have done. > > *** So...the question: Is there a good reason why you might want to NOT use > libpq.dll, and just directly access the server through direct function > calls? *** Not really. I'm skeptical that Delphi is in fact bypassing libpq. Delphi has an abstract database connection object (TDatabase etc) that requires a driver to run. Most of the drivers I've seen (Zeos, etc) wrap libpq. Some client drivers, notably JDBC, do bypass libpq. This is not 'direct function calls' but a library that implements the postgres protocol. I generally think it's a bad idea to bypass libpq, especially if your client stack has good compatibility with C libraries, which ObjectPascal does. merlin -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
