in reply to Re: What is the better way to store and display data.
in thread What is the better way to store and display data.

On the other hand, if other people need to be able to work with the data, or if there are millions of records, or if I need to do complex queries like "WHERE city = 'this' AND Status LIKE '%that%', it's probably worth the time to put it into a real database.

An in-between approach would be to use a simple CSV file, since it sounds like there aren't that many entries, but to access it as if it were a database using DBD::CSV. It's then readable and treatable like a text file, and can be easily imported into spreadsheets, but you don't have to roll your own searches through the CSV.

  • Comment on Re^2: What is the better way to store and display data.

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Re^3: What is the better way to store and display data.
by Anonymous Monk on Aug 21, 2012 at 16:22 UTC
    I like this:
    but; 
    #!/usr/bin/perl
    use strict;
    use warnings;
    use DBI;

    # Connect to the database, (the directory containing our csv file(
+s))

    my $dbh = DBI->connect("DBI:CSV:f_dir=.;csv_eol=\n;");

    # Associate our csv file with the table name 'prospects' and
    # manually declare names for each of the columns

    $dbh->{'csv_tables'}->{'prospects.csv'} = {
            'col_names' => ["name", "address", "floors", "donated", "c
+ontact"]
    };

    # Output the name and number of floors using our column names

    my $sth = $dbh->prepare("SELECT * FROM prospects.csv WHERE name LI
+KE 'G%'");
    $sth->execute();
    while (my $row = $sth->fetchrow_hashref) {
        print("name = ", $row->{'name'},
              ",   Number of floors = ", $row->{'floors'}, "\n");
    }
    $sth->finish();

    [download]

    This code is from "http://perlmeme.org/tutorials/parsing_csv.html". But running it gives this:
    DBD::CSV::st execute failed: Error 2034 while reading file /media/Micr
+oSD/code/prospects.csv: EIF - Loose unescaped quote at /usr/local/sha
+re/perl/5.14.2/SQL/Statement.pm line 1055
 [for Statement "SELECT * FROM prospects.csv WHERE name LIKE 'G%'"] at
+ propects.pl line 20.
DBD::CSV::st fetchrow_hashref failed: Attempt to fetch row without a p
+receeding execute () call or from a non-SELECT statement [for Stateme
+nt "SELECT * FROM prospects.csv WHERE name LIKE 'G%'"] at propects.pl
+ line 21.

    [download]
[reply]
[d/l]
[select]

      Try playing with different ways to connect. Your CSV does not comply to minimal CSV rules, so you'd have to loosen them or complain to the author/generator of the CSV file.

      my $dbh = DBI->connect ("dbi:CSV:", undef, undef, {
    f_dir                  => ".",      # Not needed, is default
    f_ext                  => ".csv/r", # advisable
    f_encoding             => "utf-8",  # probably needed

    csv_eol                => "\n",     # NOT needed!

    csv_allow_loose_quotes => 1,        # You /might/ need this
    csv_allow_whitespace   => 1,        # OR this

    RaiseError             => 1,        # Always a good option!
    PrintError             => 1,        # Also a good choice
    });

      [download]

      Look into the Text::CSV_XS documentation for what other csv_ options are allowed.

      FWIW, I will release a new DBD::CSV later today.


      Enjoy, Have FUN! H.Merijn
[reply]
[d/l]
[select]
      Watch for leading spaces in your file.
[reply]

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