Here, string contcatenation doesn't work with hashes

%output .= (
  'items' => [("title" => "$title")]
);
[download]

I'm guessing you want something like this:

$output{items} ||= [];
push @{$output{items}}, {title => $title};
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You should probably take a look at perldsc to see how you can use nested hashes & arrays

Also, the content type here should most likely be 'application/json'

print "Content-type: text/html\n\n";  
print $results;
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Jup, seems that way. JSON::XS is great for that stuff.

...
use JSON::XS
...
my $encoded = encode_json \%output;
...
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PerlMonks XP is useless? Not anymore: XPD - Do more with your PerlMonks XP

am still getting the same error even if i use that module

Can't modify private hash in concatenation (.) or string

am getting this error: cannot encode reference to scalar 'SCALAR(0x55c89ffbc4f0)' unless the scalar is 0 or 1

my $dbh = DBI->connect("DBI:mysql:$dbname:$host", $usr, $pwd, {
                                  RaiseError => 1,
                                  }) or die $DBI::errstr;

my $sth = $dbh->prepare("SELECT titles FROM tbl_1");
$sth->execute();
my $Data = $sth->fetchall_arrayref();
my $output;

foreach my $Data (@$Data) {
    
my ($title) = @$Data; 

$output{items} ||= [];
push @{$output{items}}, {title => $title};
}

my $encoded = encode_json \$output;

print $Cgi->header( -type => 'application/json' ),$encoded;
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use strict;
use warnings;
use 5.10.0;
use JSON;
use Data::Dump qw(pp);

my %output;

foreach my $title ("Valls", "AUT15605", "10UT15605")
{
   push @{$output{items}}, {title => $title};
}
my $output_json = encode_json \%output;
say $output_json;
pp \%output;

__END__

This is what the Perl structure looks like:
{
  items => [
    { title => "Valls" },
    { title => "AUT15605" },
    { title => "10UT15605" },
  ],
}

This is the encoded JSON:

{"items":[{"title":"Valls"},{"title":"AUT15605"},{"title":"10UT15605"}
+]}
[download]

thanks this has worked for me

%output .= (

should perhaps be

%output = (
[download]

I haven't looked at the overall logic of what you are doing but that leaps out of the page!

this returns 1 row

this returns {"items":"title","Jo0993"}

this is the format i want

({
    "items": [
       {
            "title": "Valls"
       },
       
       {
            "title": "AUT15605"
       },
       {
            "title": "10UT15605"
       }
        ]
})
[download]

My Try on ur suggestion

my $dbh = DBI->connect("DBI:mysql:$dbname:$host", $usr, $pwd, {
                                  RaiseError => 1,
                                  }) or die $DBI::errstr;

my $sth = $dbh->prepare("SELECT titles FROM tbl_1");
$sth->execute();
my $Data = $sth->fetchall_arrayref();
my %output;

foreach my $Data (@$Data) {
    
my ($title) = @$Data;

%output = (
  'items' => [("title" => "$title")]
);
}

my $encoded = encode_json \%output;

print $Cgi->header( -type => 'application/json' ),$encoded;
[download]

use strict;
use warnings;
use Data::Dumper;

my $Data =  # simulated output of fetchall_arrayref()
[
    [ 'Valls',     ('more fields')],
    [ 'AUT15605',  ('more fields')],
    [ '10UT15605', ('more fields')],
];
my %output;
@{$output{items}} = map { {title => $_->[0]} } @$Data;
print Dumper(\%output);
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They are?

my $results = to_json(\%output);
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