I'm currently developing an app that requires sending and receiving of data from android studio going to MySQL and then data coming from MySQL will be saved from the SQLite. I need advice on how to make the process faster. Right now I'm inserting 80,000 + rows of data coming from MySQL and then saving it to SQLite and that process lasts around 25-30 minutes.

This is my PHP file

rowItem.php

<?php

require "init.php";

$serial = $_POST['mySerial'];

$sql = "select ITEMCODE, DESCRIPTION, BRAND from items where SERIAL_NO = '" .$serial. "'";
$result = mysqli_query($con, $sql);

$data =array();

while($row = mysqli_fetch_array($result)) {
    $row['ITEMCODE'] = mb_convert_encoding($row['ITEMCODE'], 'UTF-8', 'UTF-8');
    $row['DESCRIPTION'] = mb_convert_encoding($row['DESCRIPTION'], 'UTF-8', 'UTF-8');
    $row['BRAND'] = mb_convert_encoding($row['BRAND'], 'UTF-8', 'UTF-8');
    array_push($data, array('ITEMCODE' => $row['ITEMCODE'], 'DESCRIPTION' => $row['DESCRIPTION'], 'BRAND' => $row['BRAND']));
}

$json = json_encode(array("allItems"=>$data));
echo $json;

?>

This is my Java code

DatabaseOperations.java

    public class DatabaseOperations extends SQLiteOpenHelper {
        public static final int dbVersion = 1;
        
        public String CREATE_ITEMS_TABLE = "CREATE TABLE " + TableData.TableInfo.TB_ITEMS +
                " (" + TableData.TableInfo.COL_ITEMS_ITEMCODE + " VARCHAR(20) PRIMARY KEY NOT NULL, " +
                TableData.TableInfo.COL_ITEMS_DESCRIPTION + " VARCHAR(50), " +
                TableData.TableInfo.COL_ITEMS_BRAND + " VARCHAR(10), " +
                TableData.TableInfo.COL_ITEMS_BARCODE + " VARCHAR(20));";
                
        public DatabaseOperations(Context context) {
            super(context, TableData.TableInfo.DB_NAME, null, dbVersion);
        }       

        @Override
        public void onCreate(SQLiteDatabase sdb) {
            sdb.execSQL(CREATE_ITEMS_TABLE);
        }
        
        public void insertItems (DatabaseOperations dop,
                                 String itemCode, String brand, String desc) {
            SQLiteDatabase sq = dop.getWritableDatabase();
            sq.beginTransaction();
            try {
                ContentValues cv = new ContentValues();
                cv.put(TableData.TableInfo.COL_ITEMS_ITEMCODE, itemCode);
                cv.put(TableData.TableInfo.COL_ITEMS_BRAND, brand);
                cv.put(TableData.TableInfo.COL_ITEMS_DESCRIPTION, desc);
                sq.insert(TableData.TableInfo.TB_ITEMS, null, cv);
                sq.setTransactionSuccessful();
            }
            catch (Exception e) {
    
            }
            finally {
                sq.endTransaction();
                sq.close();
            }
        }
    }

MainScreen.java

public class MainScreen extends AppCompatActivity {
    Context ctx = this;
    Button btnSync;
    
    String rowItemURL = "http://192.168.100.118:81/rowItem.php";
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main_screen);
        
        btnSync = findViewById(R.id.btnSync);
        btnSync.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                StringRequest itemImeiRequest = new StringRequest(Request.Method.POST, rowItemURL,
                    new Response.Listener<String>() {
                        @Override
                        public void onResponse(String response) {
                            try {
                                JSONObject jsonObject;
                                jsonObject = new JSONObject(response);
                                JSONArray itemArray = jsonObject.getJSONArray("allItems");

                                for (int i = 0; i < itemArray.length(); i++) {
                                    itemCode = itemArray.getJSONObject(i).getString("ITEMCODE");
                                    itemBrand = itemArray.getJSONObject(i).getString("BRAND");
                                    itemDesc = itemArray.getJSONObject(i).getString("DESCRIPTION");

                                    DatabaseOperations dop = new DatabaseOperations(ctx);
                                    dop.insertItems(dop, itemCode, itemBrand, itemDesc);
                                }

                                Toast.makeText(ctx, "SYNC ITEMS COMPLETED!", Toast.LENGTH_LONG).show();
                                lblDebug.setText("SUCCESS!");

                            }
                            catch (JSONException e) {
                                Toast.makeText(ctx, e.getMessage(), Toast.LENGTH_LONG).show();
                                lblDebug.setText(e.getMessage() + "500");
                            }
                        }
                    }, new Response.ErrorListener() {
                @Override
                public void onErrorResponse(VolleyError error) {
                    Toast.makeText(ctx, error.getMessage(), Toast.LENGTH_LONG).show();
                    lblDebug.setText(error.getMessage() + "511");
                }
            }) {
                @Override
                protected Map<String, String> getParams() throws AuthFailureError {
                    SharedPreferences sharedPreferencesIMEI = getSharedPreferences(IMEI_PREF, MODE_PRIVATE);
                    myIMEI = sharedPreferencesIMEI.getString(TEXT5, "");

                    Map<String,String> params = new HashMap<>();
                    params.put("mySerial", myIMEI);
                    return params;
                }
            };
            MySingleton.getInstance(MainScreen.this).addToRequestQue(itemImeiRequest);
            }
        }
    }
}

MySingleton.java

public class MySingleton {

    private static MySingleton mInstance;
    private RequestQueue requestQueue;
    private static Context mCtx;

    private  MySingleton(Context context) {
        mCtx = context;
        requestQueue = getRequestQueue();
    }

    public  RequestQueue getRequestQueue(){
        if(requestQueue==null) {
            requestQueue = Volley.newRequestQueue(mCtx.getApplicationContext());
        }
        return  requestQueue;
    }

    public static  synchronized  MySingleton getInstance(Context context) {
        if(mInstance==null) {
            mInstance = new MySingleton(context);
        }
        return  mInstance;
    }

    public<T> void  addToRequestQue(Request<T> request) {
        requestQueue.add(request);
    }
}