Select Conditional SQL Statement - php

Question

I am posting data to a URL to send a Thank You Message. The details am picking are from a table called readtextfilejson. From where I am sending Thank you messages to users.
I am however not able to select details of the only users who haven't received their text message. My code is selecting all the data and posting to all the users again and again in a loop. Thus sending multiple ThankYouMessages to users.
I have added a new column called ThankyouMessage that is by default = 'not sent'.
So that when my script runs, it updates the ThankYouMessage column to = 'SENT', so that my script can Only select details of users who haven't yet received their thankyoumessage.
Thus i don't keep re-sending the same message again and again. Kindly take a look at my script below and assist how i might resolve this.
My table structure:
<?php
$data = (string) file_get_contents($file);
//echo $data;
$data = str_replace('//Confirmation Respose', '', $data);
$data = str_replace('// Validation Response', '', $data);
$data = str_replace(' ', '', $data);
$data = preg_replace('/\s+/S', " ", $data);
$data = trim($data);
$pattern = '/\s*/m';
$replace = '';
$testString = $data;
$removedWhitespace = preg_replace( $pattern, $replace,$testString );
$removedWhitespace2 = str_replace (' ', '', $testString);
$getAllData = explode('}{', $removedWhitespace2);
foreach ($getAllData as $row) {
$row = str_replace('{', '', $row);
$rowData = explode(',"', $row);
$rowData = explode(',"', $row);
$columnValues = array();
$chkTransId = '';
foreach ($rowData as $value) {
$newVal = explode(':', $value);
$key = str_replace('"', '', $newVal[0]);
$val = str_replace('"', '', $newVal[1]);
$val = trim($val);
$columnValues[] = ($val) ? "'$val'": "''";
if($key == 'TransID'){
$chkTransId = $val;
}
}
if($chkTransId == ''){
continue;
}
////THIS IS THE SECTION AM HAVING PROBLEMS WITH - I WANT TO
////SELECT ONLY THE DATA WHERE THE COLUMN WHERE thankyoumessage =
///// 'NOT SENT'
$chkSql = "select * from `readtextfilejson`where TransID='$chkTransId'";
$getResult = mysqli_query($con, $chkSql);
$getCount = mysqli_num_rows($getResult);
$row = mysqli_fetch_object($getResult);
$text = "Dear ". $row->FirstName ." Your Payment of ". $row->TransAmount ." to XXXXX was Received Succesfully. Confirmation Code: ". $row->TransID ."";
$destination = array("messageId"=>"$product_id","to"=>"$row->MSISDN");
$product_id=uniqid();
$notifyUrl = "URL";
$notifyContentType = "application/json";
$callbackData = 'eHostOnlineCodeCheck125690';
$username = "USERNAME";
$password = "PASSWORD";
$postUrl = "POSTURL";
$message = array("from" => "USERNAME",
"destinations" => $destination,
"text" => $text,
"bulkId" => "",
"notifyUrl" => $notifyUrl,
"flash" => "false",
"notifyContentType" => $notifyContentType,
"callbackData" => $callbackData);
$postData = array("messages" => array($message));
$postDataJson = json_encode($postData);
//Submit all data to SMS server
$ch = curl_init();
$header = array("Content-Type:application/json", "Accept:application/json");
curl_setopt($ch, CURLOPT_URL, $postUrl);
curl_setopt($ch, CURLOPT_HTTPHEADER, $header);
curl_setopt($ch, CURLOPT_HTTPAUTH, CURLAUTH_BASIC);
curl_setopt($ch, CURLOPT_USERPWD, $username . ":" . $password);
curl_setopt($ch, CURLOPT_CONNECTTIMEOUT, 2);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, TRUE);
curl_setopt($ch, CURLOPT_MAXREDIRS, 2);
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $postDataJson);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
// response of the POST request
$response = curl_exec($ch);
$httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
$responseBody = json_decode($response);
curl_close($ch);
echo "<pre>";
print_r($row);
print_r($responseBody);
echo "</pre>";
$Sql = "UPDATE readtextfilejson SET thankyoumessage = 'SENT' WHERE thankyoumessage = 'not sent'";
mysqli_query($con, $Sql) or die(mysqli_error($con));
if($getCount > 0){
continue;
}
$columnValues = implode(',', $columnValues);
$sql = "INSERT INTO `readtextfilejson`(`TransactionType`, `TransID`, `TransTime`, `TransAmount`, `BusinessShortCode`, `BillRefNumber`, `InvoiceNumber`, `OrgAccountBalance`, `ThirdPartyTransID`, `MSISDN`, `FirstName`, `MiddleName`, `LastName`) VALUES (".$columnValues.")";
mysqli_query($con, $sql) or die(mysqli_error($con));
}
echo 'Data inserted successfully';
?>

Answer 1

2 possible issues.
1) You are selecting the transaction regardless of what thankyoumessage is set to. You may need to add a condition to that first SQL's where clause
SELECT * FROM `readtextfilejson`
WHERE TransID = '$chkTransId' AND thankyoumessage = 'not sent'
2) When you update the transaction thankyoumessage to "SENT" you are setting all transactions, because your update statement is missing the transaction id. You may need to add it.
UPDATE readtextfilejson
SET thankyoumessage = 'SENT'
WHERE thankyoumessage = 'not sent' AND TransID = '$chkTransId'
And since you want to set it to SENT regardless of what it was before, you may not need the thankyoumessage check either.
UPDATE readtextfilejson
SET thankyoumessage = 'SENT'
WHERE TransID = '$chkTransId'