In PDO prepare statement, for multiple insert query executing twice.why? - php

Question

database.php: //database class file
public function multipleInsert($table,$attrArray,$valuesArray) {
$sql = "INSERT INTO ".$table."(";
$array =[];
$appendValues = "";
$valuesInArray = "";
foreach ($attrArray as $key => $value) {
$sql.="".$value.", ";
}
$sql = substr_replace($sql,") VALUES ",strlen($sql)-2);
foreach ($valuesArray as $valArr) {
$valuesInArray.= "(";
foreach ($valArr as $key => $value) {
array_push($array, $value);
$valuesInArray.="?,";
}
$appendValues.= substr_replace($valuesInArray,"),",strlen($valuesInArray)-1);
$valuesInArray = "";
}
$appendValues = substr_replace($appendValues,"",strlen($appendValues)-1);
$sql.=$appendValues;
//die($sql);
$result = $this->executeQueryPRE($sql,$array);
return $result;
}
private function executeQueryPRE($sql,$arr) {
try{
$executeSQL = $this->Connection->prepare($sql);
print_r($executeSQL);die();
$executeSQL->execute($arr);
if($executeSQL) {
if($this->Connection->lastInsertId())
return $this->Connection->lastInsertId();
else
return true;
}
else
return false;
}
catch (PDOException $e) {
print "Error!: " . $e->getMessage() . "<br/>";
die();
}
}
sample.php // sample file which utilizing multiple insert query
require_once("database.php");
$Database = new Database;
$arr = ["ct_name","ct_num","ct_status"];
$arr1 = [["x","1234567890",1],["y","1234567890",1],["z","1234567890",1],["a","1234567890",1]];
$Database->multipleInsert("contact",$arr,$arr1);
Using PDO prepare statement, I am trying develop a dynamic multiple insert query. when I try to execute it, the values are getting inserted into table twice. I have gone for print_r($executeSQL) and die() option before executing it showed me a proper multiple insertion query as below.
PDOStatement Object ( [queryString] => INSERT INTO contact(ct_name,
ct_num, ct_status) VALUES (?,?,?),(?,?,?),(?,?,?),(?,?,?) )
why is it inserting twice and what is the reason and how can I overcome with this problem ?

Answer 1

Not an answer to your actual question but maybe to the actual problem you want to solve:
I don't think this string concat stuff is worth any trouble.
Takes longer for the php script to execute, pollutes the MySQL query cache, is error prone.
Therefore unless you can point to a very,very specific problem I think it loses on all points against: Just prepare a statement and execute it multiple times.
<?php
/*
table must be a valid table identifier
columns must be an array of valid field identifiers
recordData is an array of records, each itself an array of corresponding values for the fields in $columns
recordData is the only parameter for which proper encoding is taken care of by this function
*/
function foo($table, $columns, $recordData) {
$query = sprintf('
INSERT INTO %s (%s) VALUES (%s)
',
$table,
join(',', $columns) /* put in the field ids like a,b,c,d */,
join(',', array_pad(array(), count($columns), '?')) /* put in a corresponding number of ? placeholders like ?,?,?,? */
);
// resulting query string looks like INSERT INTO tablename (a,b,c,d) VALUES (?,?,?,?)
// let the MySQL server prepare that query
$stmt = $yourPDOInstance->prepare($query);
// it might fail -> check if your error handling is in place here....
// now just iterate through the data array and use each record as the data source for the prepapred statement
// this will (more or less) only transmit the statement identifier (which the MySQL server returned as the result of pdo::prepare)
// and the actual payload data
// .... as long as $yourPDOInstance->setAttribute(PDO::ATTR_EMULATE_PREPARES, false); has been set somewhere prior to the prepare....
foreach( $recordData as $record ) {
$stmt->execute( $record );
// might fail, so again: check your error handling ....
}
}
$cols = ["ct_name","ct_num","ct_status"];
$data = [
["x","1234567890",1],
["y","1234567890",1],
["z","1234567890",1],
["a","1234567890",1],
];
foo("contact", $cols, $data);
(script is tested by php -l only; no warranty)
see also: http://docs.php.net/pdo.prepared-statements