React Native Login connect with sql server ?

Question

I created a Login application that connects to the sql server using Visual Studio Code. The Login and SignUp application logs into the sql server to read the Table 'TABUSERNAME' and export it to the grid, but I get an error, my computer's sql server information:

user: 'sa'
pass: 'Coffee'
server:'MICROSOFT' or '192.168.1.100'
database: 'Cafe'

Can you please fix my code errors ?

File: App.js

Tuhin Paul · Answer

Connection String: Double-check the format and values of your connection string ensuring they align with your SQL Server configuration. Verify server name instance name (if applicable) database name authentication mode and credentials. Credentials: Confirm that you're using the correct username and password for the SQL Server account. Database Server Accessibility: Ensure your application can reach the SQL Server instance on the specified network address or server name. Check for firewall restrictions or network connectivity issues. Table Name: Verify that the table name 'TABUSERNAME' is spelled correctly and exists in the 'Cafe' database. pen_spark

Jayraj Chhaya · Answer

Share error details so we can understand the problem and find the solution for it.

Dong Lam Trien · Answer

I posted a previous post and couldn't send the code so this page reported an error so I resubmitted it When it's running I enter user and password and press the login button I get an error: ERROR Cannot convert null value to object //App.js import React { useState } from 'react'; import { StyleSheet View TextInput Button FlatList Text } from 'react-native'; import SQLite from 'react-native-sqlite-storage'; //import axios from 'axios'; const App = () => { // Kh?i t?o state s? luu tr? thông tin ngu?i dùng const [username setUsername] = useState(''); const [password setPassword] = useState(''); const [sqliteData setSqliteData] = useState([]); // Thêm 'sqliteData' vào danh sách các state // Hàm x? lý khi ngu?i dùng nh?n nút Login const handleLogin = async () => { //alert('login'); //console.log('login1'); try { // K?t n?i b?ng co s? d? li?u const db = SQLite.openDatabase( { name: 'Cafe.db' location: 'default' //createFromLocation: '~www/test.db' } () => { console.log('Connected to the database.'); } (error) => { console.error('Failed to connect to the database.' error); } ); // Th?c hi?n truy v?n SQL s? lây d? li?u t? b?ng db.transaction(tx => { tx.executeSql( 'SELECT * FROM TABUSERNAME' [] (_ result) => { if (result.rows) { const rows = result.rows.raw(); setSqliteData(rows); // Luu tr? d? li?u t? SQLite vào state 'sqliteData' } else { console.log('No rows returned from the query.'); } } error => { console.error('Failed to execute query.' error); } ); }); // Ðóng k?t n?i co s? d? li?u khi không s? d?ng n?a //return () => { db.close(); console.log('Database connection closed.'); //}; } catch (error) { console.error(error.message); } }; // Hàm x? lý khi ngu?i dùng nh?n nút Signup const handleSignup = async () => { try { // } catch (error) { console.error(error.message); } }; return ( {/* Hi?n th? d? li?u trong ô lu?i */} {JSON.stringify(item)} } keyExtractor={(_ index) => index.toString()} /> {/* ngu?i dùng nh?p tên ngu?i dùng */} {/* ngu?i dùng nh?p m?t kh?u */} {/* Nút s? th?c hi?n ch?c nang dang nh?p */} {/* Nút s? th?c hi?n ch?c nang dang ký */} ); }; export default App; const styles = StyleSheet.create({ container: { flex : 1 backgroundColor : '#e7feff' } flatlist: { //top : 340 //width : 50 //height : 50 backgroundColor : 'red' } inputText : { top: 340 } text : { marginLeft : 30 } button : { width : 360 height : 150 marginHorizontal : 20 justifyContent : 'center' } login : { } signup : { top : 20 } }) // server.js const express = require('express'); const bodyParser = require('body-parser'); const sql = require('mssql'); const app = express(); const port = 3000; app.use(bodyParser.json()); const config = { user: 'sa' password: '123456' server: 'MICROSOFT' database: 'Cafe' options: { encrypt: false // N?u không s? d?ng k?t n?i b?o m?t d?t encrypt là false } }; app.post('/login' async (req res) => { const { username password } = req.body; try { await sql.connect(dbConfig); const query = `SELECT * FROM TABUSERNAME WHERE USERNAME = @username AND PASSWORDS = @password`; const request = new sql.Request(); request.input('username' sql.VarChar username); request.input('password' sql.VarChar password); const result = await request.query(query); if (result.recordset.length > 0) { res.json({ success: true message: 'Login successful' }); } else { res.status(401).json({ success: false message: 'Login failed' }); } } catch (err) { console.error('Database connection error' err); res.status(500).json({ success: false message: 'Internal server error' }); } finally { sql.close(); } }); /* app.post('/login' async (req res) => { try { await sql.connect(config); const result = await sql.query(`SELECT * FROM TABUSERNAME WHERE USERNAME='${req.body.username}' AND PASSWORDS='${req.body.password}'`); sql.close(); res.json(result.recordset); } catch (error) { res.status(500).send(error.message); } }); */ app.listen(port () => { console.log(`Server is running on port ${port}`); });