[vox-tech] sqlite + perl - wierd unrecognized token error

[Peter Jay Salzman]

On Thu 23 Dec 04,  1:09 PM, Henry House <hajhouse at houseag.com> said:
> På torsdag, 23 december 2004, skrev Peter Jay Salzman:
> > On Thu 23 Dec 04, 11:15 AM, Shwaine <shwaine at shwaine.com> said:
> > > On Thu, 23 Dec 2004, Peter Jay Salzman wrote:
> > > <snip>
> > > >  DBD::SQLite::db do failed: unrecognized token: ":" at Create_Tables.pm 
> > > >  line
> > > >  52, <> line 6.
> > > >
> > > <snip>
> > > >Excerpt from Create_Tables.pm:
> > > >
> > > <snip>
> > > >     my $dbh = DBI->connect("dbi:SQLite:$table_name");
> > > >
> > > <snip>
> > > >Statement handle DBI::st=HASH(0x840773c) DESTROY ignored - never set up
> > > >       ERROR: 1 'unrecognized token: ":"' (err#0)
> 
> This error seems to be coming from failure of the string cotaining the SQL
> to be interpolated as expected. Changing the code to this:
> 
> 
> 	use DBI;
> 
>    sub Create_Course()
>    {
>       my %course;
> 
>       print "Enter semester: ";
>       $course{semester} = <>;
> 
>       print "Enter course: ";
>       $course{course} = <>;
> 
>       print "Enter Course Desc: ";
>       $course{course_desc} = <>;
> 
>       print "Enter college: ";
>       $course{college} = <>;
> 
>       print "Enter reference: ";
>       $course{reference} = <>;
> 
>       foreach (keys %course) { chomp $course{$_}; }
> 
>       Create_Database(\%course);
>    }
> 
>    sub Create_Database(%)
>    {
>       my ($course) = @_;
> 
>       my $table_name =
>          "$course->{semester}.$course->{course}.$course->{reference}.dat";
> 
>       die "Database file already exists" if -e $table_name;
> 
>       my $dbh = DBI->connect("dbi:SQLite:$table_name");
> 
>       # Create the course table
>       #
>       $dbh->do("
>          CREATE TABLE course (
>             semester    VARCHAR(10),
>             course      VARCHAR(10),
>             course_desc VARCHAR(10),
>             college     VARCHAR(20),
>             reference   INT
>          )
>       ");
> 
> 
>       # Populate the course table.  FIXME.  Clunky.
>       #
> 		my $sql = "INSERT INTO course VALUES ( "
>             . $dbh->quote ( $course->{semester} ) 
>             . ', ' . $dbh->quote ( $course->{course} )
>             . ', ' . $dbh->quote ( $course->{course_desc} )
>             . ', ' . $dbh->quote ( $course->{college} )
>             . ', ' . $dbh->quote ( $course->{reference} )
>          	. " )";
> 		printf("%s\n", $sql);
> 		$dbh.do($sql);
>    }
> 
> 	Create_Course();
> 
> gets rid of this error:
> 
> # I'm getting an error message that I don't know how to fix:
> [...]
> #    DBD::SQLite::db do failed: unrecognized token: ":" at Create_Tables.pm line
> #    52, <> line 6.
 

Yeah.  Actually, I used sprintf which seems tailor made for exactly this
purpose:

   $_ = sprintf("%s (%s, %s, %s, %s, %s)",
            "INSERT INTO course VALUES",
            $dbh->quote( $course->{semester} ),
            $dbh->quote( $course->{course} ),
            $dbh->quote( $course->{course_desc} ),
            $dbh->quote( $course->{college} ),
            $dbh->quote( $course->{reference} )
        );

> Unfortunately, it still does not work; the table is created but the insert
> fails silently. I don't have time to figure it our right now, but I suggest
> using the sqlite program to view the database file for debugging purposes
> and to try the SQL there to make sure it works because if it subsequently
> fails in perl you will know that you have a perl problem rather than an SQL
> problem. I hope this helps!

Strange -- it seems to work for me:


   p at satan$ ./driver.pl


   Grade Utility
   +-=-=-=-=-=-=-=-=-=-+
   1. Create a new class
   2. Add a student
   3. Modify a record
   4. Print_Record()
   5. Dump A Course Table
   q. Quit
   +-=-=-=-=-=-=-=-=-=-+

   Choice: 5
   Enter database name: 20051.Phy101.1234.dat
   semester:    20051
   course:      Phy101
   course_desc: College Physics I
   college:     MCCC
   reference:   1234


Damn.  I think I'm really starting to understand multi-file perl programs,
and how to write packages and modules.  Scary -- I never thought I'd grok
that stuff.

Now I just need to conquer grokking Perl's object oriented stuff.   It takes
so much darn *effort* just to write a stupid class.  I hope Perl6 simplifies
the process.  Seems like people have been talking about Perl6 for well over
2 years now.  I can't wait to write...

   if ( condition )
      do_something;

without the stupid Freedom-braces!!!    ;-)

Pete

-- 
The mathematics of physics has become ever more abstract, rather than more
complicated.  The mind of God appears to be abstract but not complicated.
He also appears to like group theory.  --  Tony Zee's "Fearful Symmetry"

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