Array execute in php if empty pdo php [duplicate] - php

Question

This question already has answers here:
PHP PDO Insert Using Loop
(2 answers)
Closed 5 months ago.
foreach($parentinfojson as $value) {
if (!empty($parentinfojson )) {
$stmt2 = $dbh -> prepare("INSERT INTO parentinfo (last_name,first_name,status) VALUES (:lastname,:firstname,:status)");
$stmt2_ = $stmt2 -> execute(array(':firstname' => $value['firstname'], ':lastname' => $value['lastname'], ':status' => $status));
} else {
$stmt2_ = $stmt2 -> execute();
}
}
if ($stmt2_ && $stmt3_ && $stmt1_ && $stmt_ && $stmt5_ && $stmt4_) {
echo json_encode(array(
'error' => false,
'message' => "Added"
));
}
This is my execute in Inserting new data in the table. When i tested the adding of empty data(parentinfojson is empty) i get error that Notice: Undefined variable: stmt2_. What i did is i added an else statement and i initialize the variable still i get error. I tried to echo something in the else statement as well but i get error. Now I run out of idea on how to initialize the variable when the json is empty so that i dont get the error undefined variable

Answer 1

You just defined $stmt2 inside the loop, if $parentinfojson is empty it'll certainly get undefined. Why not define/initialize it.
// initialize up top
$stmt_ = $stmt1_ = $stmt2_ = $stmt3_ = $stmt4_ = $stmt5_ = false;
$stmt2 = $dbh->prepare("INSERT INTO parentinfo (last_name,first_name,status) VALUES (:lastname,:firstname,:status)");
foreach($parentinfojson as $value) {
$stmt2_ = $stmt2->execute(array(
':firstname' => $value['firstname'],
':lastname' => $value['lastname'],
':status' => $status
));
}
if ($stmt2_ && $stmt3_ && $stmt1_ && $stmt_ && $stmt5_ && $stmt4_) {
echo json_encode(array(
'error' => false,
'message' => "Added"
));
}
Sidenote: Another way would be to build the query dynamically, including the placeholders and the values. So that in turn, you don't have to loop each batches of insert but instead, creating the SQL batch insert then binding all of the values into one single insert invocation:
$stmt_ = $stmt1_ = $stmt2_ = $stmt3_ = $stmt4_ = $stmt5_ = false;
if(!empty($parentinfojson)) {
$base_query = 'INSERT INTO parentinfo (last_name, first_name, status) VALUES ';
$placeholders = implode(',', array_map(function($batch){
return '(' . implode(',', array_fill(0, count($batch), '?')) . ')';
}, $parentinfojson));
$base_query .= $placeholders;
$parentinfojson = call_user_func_array('array_merge', array_map('array_values', $parentinfojson));
$stmt2 = $dbh->prepare($base_query);
$stmt2_-> $stmt2->execute($parentinfojson);
}

Answer 2

There might be a chance that the json variable you are receiving is not empty, so you should also add a check for valid json, this is the function to check a valid json
function isJson($string) {
json_decode($string);
return (json_last_error() == JSON_ERROR_NONE);
}