Sending Arduino data to mySQL database using NodeMCU ESP8266

Kindly help me in my code. I have arduino code that is sending and getting data from mySql. It is running well and storing data to the database. The problem is that, if I switch ON the button the value 1 is stored in the database, but when I switch OFF the button the value 0 is not stored in the database.

Here is my arduino code:

//Arduino Code
#include <SoftwareSerial.h>

SoftwareSerial s(5,6);//Rx,Tx
int buttonPinBulb = 11;
int relay1 = 10;
int buttonBulb;
int currentStatus = LOW;
unsigned long lastMillis = 0;
const unsigned long debounceTime = 100;

void setup() {
  // put your setup code here, to run once:
  pinMode(buttonPinBulb, INPUT_PULLUP);
  pinMode(relay1, OUTPUT);
  s.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
  buttonBulb = digitalRead(buttonPinBulb);
  bulbOnOff(buttonBulb);
}

int bulbOnOff(int buttonBulb) {
  unsigned long currentMillis = millis();
  // protect against overflow
  if ( (currentMillis - lastMillis > debounceTime) || (currentMillis < lastMillis)) {

    if (buttonBulb != currentStatus) {
      digitalWrite(relay1, buttonBulb);
      //Serial.println(!buttonBulb);
      currentStatus = buttonBulb;

      // update database here
      if(s.available()>0)
            {
            s.write(!buttonBulb);
            }

      lastMillis = currentMillis;
    }
  }
  return 0;
}

The following is nodeMCU ESP8266 code

#include <ESP8266WiFi.h>
#include <WiFiClient.h>
#include <ESP8266WebServer.h>
#include <ESP8266HTTPClient.h>
#include <SoftwareSerial.h>

SoftwareSerial s(D6, D5); //RX,TX
int buttonBulb;
int Led_OnBoard = 2;
const char* ssid = "iPhone";                  // Your wifi Name
const char* password = "Qaser.shah.123";          // Your wifi Password
const char *host = "172.20.10.6"; //Your pc or server (database) IP, example : 192.168.0.0 , if you are a windows os user, open cmd, then type ipconfig then look at IPv4 Address.

void setup() {
  // put your setup code here, to run once:
  wifiConnection();
  s.begin(115200);
}

int wifiConnection() {
  pinMode(Led_OnBoard, OUTPUT);       // Initialize the Led_OnBoard pin as an output
  Serial.begin(115200);
  WiFi.mode(WIFI_OFF);        //Prevents reconnection issue (taking too long to connect)
  delay(1000);
  WiFi.mode(WIFI_STA);        //This line hides the viewing of ESP as wifi hotspot

  WiFi.begin(ssid, password);     //Connect to your WiFi router
  Serial.println("");

  Serial.print("Connecting");
  // Wait for connection
  while (WiFi.status() != WL_CONNECTED) {
    digitalWrite(Led_OnBoard, LOW);
    delay(250);
    Serial.print(".");
    digitalWrite(Led_OnBoard, HIGH);
    delay(250);
  }

  digitalWrite(Led_OnBoard, HIGH);
  //If connection successful show IP address in serial monitor
  Serial.println("");
  Serial.println("Connected to Network/SSID");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());  //IP address assigned to your ESP
  Serial.begin(115200);
}

void loop() {
  // put your main code here, to run repeatedly:
  s.write("s");
  if (s.available() > 0)
  {
    buttonBulb = s.read();
    Serial.println(buttonBulb);
    int result = updateDatabase(buttonBulb);
    if(result != 0){
      //error updating database
      Serial.print("error updating database");
      }
  }
}

int updateDatabase(int buttonBulb){
    HTTPClient http;    //Declare object of class HTTPClient

  //String ButtonState;
  String buttonValueSend, postData;
  
  buttonValueSend = String(buttonBulb);   //String to interger conversion
 
  //Post Data
  postData = "buttonBulb=" + buttonValueSend;
  
  http.begin("http://172.20.10.6/Nodemcu_db_record_view/InsertDB.php");              //Specify request destination
  http.addHeader("Content-Type", "application/x-www-form-urlencoded");    //Specify content-type header

  int httpCode = http.POST(postData);   //Send the request
  String payload = http.getString();    //Get the response payload
  
  Serial.println(httpCode);   //Print HTTP return code
  Serial.println(payload);    //Print request response payload
  Serial.println("Button Value send=" + buttonValueSend);

  http.end();  //Close connection
  return 0;
  }

The following is my php code which stores the Arduino data

<?php
//Creates new record as per request
    //Connect to database
    $servername = "localhost";      //example = localhost or 192.168.0.0
    $username = "root";     //example = root
    $password = ""; 
    $dbname = "automation";

    // Create connection
    $conn = new mysqli($servername, $username, $password, $dbname);
    // Check connection
    if ($conn->connect_error) {
        die("Database Connection failed: " . $conn->connect_error);
    }

    //Get current date and time
    date_default_timezone_set('Asia/Karachi');
    $d = date("Y-m-d");
    $t = date("H:i:s");

    if(!empty($_POST['buttonBulb']))
    {
        $buttonBulb = $_POST['buttonBulb'];
        
        $sql = "INSERT INTO project (ButtonState, Date, Time) VALUES ('".$buttonBulb."', '".$d."', '".$t."')"; //nodemcu_ldr_table = Youre_table_name

        if ($conn->query($sql) === TRUE) {
            echo "OK";
        } else {
            echo "Error: " . $sql . "<br>" . $conn->error;
        }
    }

    $conn->close();
?>

See the image of output In this image OK is printing at Value 1 but not printing OK at value 0

I think there is something wrong or I forgot something, that is why it is not happening.

Thanks a lot for any appericiation.