Simple interaction with database via DBI module

DBI module

You should make sure that module DBI has been installed on your pc, then follow the bellow steps:

1. use DBI module in your perl script

use DBI;

1. Declare some primary parameters

my $driver = "MyDriver";

my $database = "DB_name";

my $dsn = "DBI:$driver:dbname=$database";

my $userid = "your_user_ID";

my $password = "your_password";

my $tablename = "your_table";

1. Connect to your database

my $dbh = DBI->connect($dsn, $userid, $password);

1. Prepare your query

my $query = $dbh->prepare("Your DB query");

Ex:

$my_query = qq/SELECT * FROM table WHERE column1 = 2/;

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

We can also use variable in the query, like below:

my $table_name = "table";

my $filter_value = 2;

$my_query = qq/SELECT * FROM $table_name WHERE column1 = $filter_value/;

1. Execute your query

$query->execute();

*Note: To avoid injection attack, you should use placeholders ? instead of put your variable in the query.

Ex: you want to show the all data from 'table' where column1=$value1 and column2=$value2:

my $query = $dbh->prepare("SELECT * FROM table WHERE column1 = ? AND column2 = ?;");

$query->execute($value1, $value2);

1. Fletch your data

my @row = $query->fetchrow_array(); store data as array

or

my $ref = $sth->fetchrow_hashref(); store data as hash reference

1. Finish and disconnect DB

$sth->finish;

$dbh->disconnect();

Parameters

Column	Column
$driver	Driver for DB, "Pg" for Postgresql and "mysql" for MySQL
$database	your database name
$userid	your database id
$password	your database password
$query	put your query here, ex: "select * from $your_table"