Dear Monks

I have been writing many objects for a while and most of them fall into the general pattern of simply wrapping a mySQL table. They load a record from the table put the variables into the object hash and then get and set functions manipulate the data and provide input correctness and output formatting.

I did this previously by every field having a get and set method which got the data from the database or wrote directly to the database. It worked but it is not very efficient.

Basically my code consisted of many many verions of this: 

sub get_user_name( $ )
{
   my $data;
   my $query;   

   my $self = shift;

   my $dbh  = $self->{'dbh'};   
    

   my $sqlQuery = "SELECT UserName 
                     FROM USERINFORMATION                     
                    WHERE UserID = \'$self->{user_id}\'";
                        
    $query = $dbh->prepare( $sqlQuery );
      
    $query-> execute() || die $dbh->errstr;

    if( $data = $query->fetchrow_array() )
    {       
        $self->{'error_type'}   = "";   
        $self->{'error_string'} = "";   
        return( $data );
                            
     }
     else
     {
         $self->{'error_type'}   = "variable returned no value";   
         $self->{'error_string'} = "variable returned no value";    
         return( undef ); 
     }  
   
}  





sub update_user_name( $ )
{
   my @data;
   my $query;   

   my $self = shift;

   my $dbh  = $self->{'dbh'};   
    
   # Test for zero length input and 
   if( $_[0] eq "" )
   {
      
      $self->{'error_type'}   = "blank";   
      $self->{'error_string'} = "This variable must be filled in."; 
      return( undef );  
   
   }
    
   # test for input string being too long
   elsif( length( $_[0] ) > 20 )
   {
      
    $self->{'error_type'}   = "overlength";   
      $self->{'error_string'} = "This variable may only be 20 characte
+rs."; 
      return( undef );  
   
   } 
    
   # test for chracter correctness
   elsif( $_[0] =~ /[^A-Za-z0-9_]/  )
   {
         
    $self->{'error_type'}   = "illegal characters";   
      $self->{'error_string'} = "Only the chracters A-Z a-z 0-9 _ are 
+allowed.";    
      return( undef );  
   
   }
   
   # test for variable specific cases here

   # username must be unique
   
   
   my $sqlQuery = "SELECT UserID, UserName
                     FROM USERINFORMATION
                    WHERE UserName = \'$_[0]\'";

   my $query = $dbh->prepare( $sqlQuery );

   $query->execute() || die $dbh->errstr;

   @data = $query->fetchrow_array();
   
   #if the userid of the duplicate groupname
   #matches the current userid of the person
   #registering the system then proceed 
   if( $data[0] != $self->{'user_id'} && $data[1] ne "" )  
   { 
   
        $self->{'error_type'}   = "not unique";   
        $self->{'error_string'} = "User Name already in use please cho
+ose another.";    
        return( undef );        
   }
   

   else
   {
        my $update = &format_for_mysql( $_[0] );
       
        my $sqlQuery = "UPDATE USERINFORMATION
                          SET UserName = \'$update\'
                          WHERE UserID = $self->{user_id}";
                        
        $query  = $dbh->do( $sqlQuery );
      
         return( 1 );
      
    
    }

}

[download]

Now I wonder since 90 percent of my objects simply wrap a table like the above code is there a better way?

Edit by tye, add READMORE tag

In reply to Writing Better Objects by Angel

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.