RuddWire » mySQL

Perl script make MySQL query, binds variables, outputs JSON

Colin — Sat, 17 Jul 2010 00:40:11 +0000

An example of a Perl script that is called by an ajax request. The script takes in just one parameter, opens a MySQL DB connection, binds the parameter to the query, and sends the query. The result is then formatted into JSON and returned to the browser.

This can be seen in action on this page: http://www.ruddwire.com/friendly-data/naics-explorer/, in the NAICS search box.

 
#!/usr/bin/perl
 
use strict;
use DBI();
use CGI qw(:standard);
 
 
my $dbh;
my $sth;
my $mySQL;
my $result = '({"failure":1})';
 
#QUERY PARAMS
my $q;
 
 
 
my $ref;
my $table = "";
my $tableRow;
 
my $query = new CGI;
 
 
 
 
 
if($query->param()){
 
 
    $q = $query->param('q');
    $q =~ s/\s+/%/;  # REPLACE SPACES WITH WILD CARD CHARACTER, CAUSES TO SEARCH FOR ALL WORDS, NOT JUST PHRASE
 
    ### Connect to the database.
	my $dbh = DBI->connect("DBI:mysql:database=***DBNAME***;host=localhost",
                         "***USERNAME***", "***PASSWORD***",
                         {'RaiseError' => 1});
 
    	### GET INDUSTRY NAME AND CODE
    	$mySQL = "SELECT code,industry FROM naics2007IndustryIndex WHERE industry LIKE ? ORDER BY industry";
 
 
     $sth = $dbh->prepare($mySQL);
     $sth->execute("%".${q}."%");
 
      while ($ref = $sth->fetchrow_hashref()) {
 
		  while ((my $key, my $value) = each(%$ref)){
		  	  $value =~ s/"/\\"/g;
			  $tableRow .= "\"${value}\",";
		  }
 
		  $tableRow =~ s/,$//;
		  $tableRow = "[${tableRow}],";
 
		  $table .= $tableRow;
		  $tableRow = "";
      }
 
		$table =~ s/,$//;
 
	  	$result = '{"failure":0,"result":['.$table.']}';         
 
}### END IF QUERY
 
 
 
print "Content-type: text/javascript; charset=iso-8859-1\n\n";
 
print $result;
 
exit(0);

Perl script makes MySQL query; outputs to JSON

Colin — Mon, 21 Jun 2010 01:37:34 +0000

An example of a Perl script that is called by an ajax request. The script takes in a few parameters, opens a MySQL DB connection, and then makes a rather tortuous query. The result is then formatted into JSON and returned to the browser.

This can be seen in action on this page: http://www.ruddwire.com/friendly-data/naics-explorer/.

#!/usr/bin/perl
 
use strict;
use DBI();
use CGI qw(:standard);
 
 
my $dbh;
my $sth;
my $mySQL;
my $result = '({"failure":1})';
 
#QUERY PARAMS
my $strLn;
my $classification;
my $getDef;
my $getIndus;
 
my $naicsMatch = "";
my $countMatch = "";
my @subClasses;
my $ref;
my $table = "";
my $tableRow;
 
 
sub scrubInputText {
 
   my($it) = @_;
   my $shellChars = q-[&;`'\\\"\|\*\?\~<>\^\(\)\[\]\{\}\$\\n\\r]-;    #`
 
    $it =~ s/$shellChars//g;
    $it =~ s/^\s+|\s+$//g;
 
   return $it;
 
}
 
 
my $query = new CGI;
 
if($query->param()){
 
    $strLn = &scrubInputText($query->param('strLn'));
    $classification = &scrubInputText($query->param('cls'));
    $getDef = &scrubInputText($query->param('getDef'));
    $getIndus = &scrubInputText($query->param('getIndus'));
 
    ###HANDLE GROUPED SECTOR CODES, IE: 31-33
    if($classification =~ /-/){
    	@subClasses = split("-",$classification);
		$naicsMatch = "AND (";
 
		for(my $subClass = $subClasses[0]; $subClass <= $subClasses[1]; $subClass++){
    		$naicsMatch .= "code LIKE '${subClass}%' OR ";
    		$countMatch .= "code LIKE '${subClass}%' OR ";
    	}
    	$countMatch =~ s/ OR $//;
    	$naicsMatch =~ s/ OR $//;
    	$naicsMatch .= ")";
    }else{
       $naicsMatch = "AND code LIKE '${classification}%'";
    }
 
	if($strLn != 2){$countMatch = "code LIKE Concat(naics2007.code,'%')";}
 
    ### Connect to the database.
	my $dbh = DBI->connect("DBI:mysql:database=***DBNAME***;host=localhost",
                         "***USERNAME***", "***PASSWORD***",
                         {'RaiseError' => 1});
 
    if($getDef){
    	$mySQL = "SELECT definition FROM naics2007definitions WHERE code='${classification}'";
    }elsif($getIndus){
    	### GET FINAL INDUSTRY NAME
    	$mySQL = "SELECT code,industry FROM naics2007IndustryIndex WHERE code LIKE '${classification}' ORDER BY industry";
    }else{
    	### GET INDUSTRY CLASSIFICATIONS
 
 
 		$mySQL = "SELECT code,title, ".
     	"(SELECT COUNT(code) FROM naics2007IndustryIndex WHERE ".
     	"CASE naics2007.code ".
     	"WHEN '31-33' THEN (code LIKE '31%' OR code LIKE '32%' OR code LIKE '33%') ".
     	"WHEN '44-45' THEN (code LIKE '44%' OR code LIKE '45%') ".
     	"WHEN '48-49' THEN (code LIKE '48%' OR code LIKE '49%') ".
     	"ELSE code LIKE Concat(naics2007.code,'%') END) AS c".
     	" FROM naics2007 WHERE (CHAR_LENGTH(code) = $strLn OR code LIKE '__-__')".$naicsMatch;
 
    }
 
 
     $sth = $dbh->prepare($mySQL);
     $sth->execute();
 
      while ($ref = $sth->fetchrow_hashref()) {
 
		  while ((my $key, my $value) = each(%$ref)){
		  	  $value =~ s/"/\\"/g;
			  $tableRow .= "\"${value}\",";
		  }
 
		  $tableRow =~ s/,$//;
		  $tableRow = "[${tableRow}],";
 
		  $table .= $tableRow;
		  $tableRow = "";
      }
 
		$table =~ s/,$//;
 
	  	$result = '{"failure":0,"result":['.$table.']}';
 
}### END IF QUERY
 
 
 
print "Content-type: application/json; charset=iso-8859-1\n\n";
 
print $result;
 
exit(0);

Handy MySQL Commands

Colin — Sun, 25 Apr 2010 22:30:20 +0000

To reset an auto_increment field to 1:

ALTER TABLE tbl_name AUTO_INCREMENT = 1;

To load a local csv file into an empty existing table:

LOAD DATA LOCAL INFILE ‘/completePathToLocalData.csv’ INTO TABLE tableName FIELDS TERMINATED BY ‘,’ ENCLOSED BY ‘”‘ LINES TERMINATED BY ‘\n’ IGNORE 1 LINES;

This assumes you’ve already created your empty table with the same number of fields that your csv file has.