Reputation: 101
I want to make a query to a sqlite database and return an array of objects.
I'm creating a telegram bot and i have to store the date of last message per user_id, because telegram API returns messages i've already read. So i've created a sqlite db with two tables: users and messages; users contains all the user_id and username; messages contains the last message_id i've read.
I've done this function, it works but it isn't performing very well because it has to recreate the entire array of objects (fetchrow_hashref).
sub sqlLiteSelect {
my ($db,$table,$columnsRef,$where,$others) = @_;
my $columns = join(', ', @{ $columnsRef });
$others ||= '';
my $query = "select ${columns} from ${table} ${where}${others}";
my $obj = $db->prepare($query);
my $ret = $obj->execute() or die $DBI::errstr;
my @array = ();
while(my $row = $obj->fetchrow_hashref) {
my $tmp = {};
foreach my $column (@{ $columnsRef }) {
$tmp->{$column} = $row->{$column};
}
push @array, $tmp;
}
return @array;
}
my @columns = ('user_id','first_name','username','type');
my $where = ' where user_id in (1,2)';
my @result = sqlLiteSelect($db,'users',\@columns,$where,'');
foreach my $row (@result) {
print "user_id=$row->{user_id}, username=$row->{username}\n";
}
I expect my select to return an array of object without recreate it everytime.
Upvotes: 0
Views: 1657
Reputation: 954
my ($user_id, $first_name, $username, $type);
my $sql = q{
SELECT user_id, first_name, username, type
FROM users
WHERE user_id IN (1,2)
};
my $sth = $db->prepare($sql);
$sth->execute or die $DBI::errstr;
$sth->bind_columns(\$user_id, \$first_name, \$username, \$type);
while ($sth->fetch) {
print "$user_id, $username\n";
}
read the documentation https://metacpan.org/pod/DBI#bind_columns
Upvotes: 2