Re: AWS Entry into the TechEmpower Framework Benchmark Project

[ake.ragnar.dahlgren@gmail.com]

On Tuesday, November 19, 2013 3:59:04 AM UTC+1, Shark8 wrote:
> TechEmpower is Benchmarking different frameworks for web-development ( http://www.techempower.com/benchmarks/#section=motivation&hw=i7&test=json ). There was no entry for AWS, or any other Ada showing (I know there's matreshka, and IIRC several Ada/CGI bindings), so I coded one up. Unfortunately there is no DB-functionality in it right now, as I couldn't get the ODBC to work, nor could I find a working InterBase (or FireBird) binding for Ada.

Using GNATCOLL it's possible to "talk" to a SQLite or PostgreSQL database. To use it you use a text file to describe the tables of your database (the schema). Then you use the executable gnatcoll_db2ada to generate the tables in the database (I've only used it for PostgreSQL), and then you use the same tool to generate the Ada code to be used by your application. Example usage:

To create the tables in the PostgreSQL database:
gnatcoll_db2ada -dbmodel=database_description.txt -dbhost=localhost -dbport=5432 -dbname=database_name -dbuser=user_name -dbpasswd=some_password -createdb

To generate the Ada files:
gnatcoll_db2ada -dbmodel=database_description.txt -api=Auto_Generated_Database_API

When using the SQL database in the Ada code you need the Connection instance.

         Description : GNATCOLL.SQL.Exec.Database_Description;
         Connection  : GNATCOLL.SQL.Exec.Database_Connection;

      Description := GNATCOLL.SQL.Postgres.Setup(Database      => Database_Name,
                                 User          => User_Name,
                                 Host          => Host_URL,
                                 Password      => User_Password,
                                 SSL           => Postgres.Allow,
                                 Cache_Support => True);
      Connection := GNATCOLL.SQL.GNATCOLL.SQL.Exec.Get_Task_Connection(Description  => Description);

When you are finished talking to the database (i.e. when it's time to shutdown the application) you need to:

      GNATCOLL.SQL.Exec.Free (Connection);
      GNATCOLL.SQL.Exec.Free (Description);

You can for example construct an SQL statements by:

      Query_Insert : constant GNATCOLL.SQL.SQL_Query :=
        GNATCOLL.SQL.SQL_Insert(Values => ...);

Before using it you always need to reset the connection to the database by:
      Connection.Reset_Connection;
Then you can execute the SQL statement using the connection instance:
      ... := Connection.Insert_And_Get_PK(Query => Query_Insert,
                                          PK => Auto_Generated_Database_API...);

For further details please read the GNATCOLL documentation.

Best regards,
Åke Ragnar Dahlgren