[Hiki] update - tut-libgda-errors (ruby-gnome2-doc-cvs) - Ruby-GNOME2

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REMOTE_ADDR = 217.117.55.140
REMOTE_HOST = 
        URL = http://ruby-gnome2.sourceforge.jp/?tut-libgda-errors
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  = Managing errors

  You can manage errors using the Gda::Error class, and obtain objects with the method Gda::Connection#errors.

  A GDA error contains 4 distinct piece of information.

  :Gda::Error#description
   A full description of the error. 

  :Gda::Error#number
   Error's number.

  :Gda::Error#source
   Error's source.

  :Gda::Error#sqlstate
   SQL state.

  Here you can see an example of using this:

    def show_errors(conn)
        # Obtains errors list and loop for getting error information.
        conn.errors.each do |error|
            puts "Error no: #{error.number.to_s}"
            puts "Description: #{error.description}"
            puts "Source: #{error.source}"
            puts "SQL state: #{error.sqlstate}"
        end
    end

  Usually, you can check errors when Gda::Connection query methods fail.  For instance:

    # For Gda::Connection#execute_non_query:
    if conn.execute_non_query(cmd) == -1
        show_errors(conn)
    end

    # For Gda::Connection#execute_single_command:
-   ds = conn.execute_single_command(cmd)
-   if ds.nil?
+   dm = conn.execute_single_command(cmd)
+   if dm.nil?
        show_errors(conn)
    end

    # For Gda::Connection#execute_command:
    arr = conn.execute_command(cmd)
-   arr.each do |ds|
-       if ds.nil?
+   arr.each do |dm|
+       if dm.nil?
            show_errors(conn)
        end
    end

  Also, it is possible to be notified with a GLib signal when an error occurs:

    conn.signal_connect('error') { show_errors(conn) }

Ruby-GNOME2

[ruby-gnome2-doc-cvs] [Hiki] update - tut-libgda-errors