When creating a react native project the app.js file can't be create ?

Lam trien dong — Wed, 08 May 2024 09:31:32 +0000

I type the command in cmd: npx create-expo-app loginHAT when creating the project in the loginHAT folder there is no App.js file? How to fix this error ?

Connection fail to SQL Server using NodeJS mssql msnodesqlv8 from the server ?

Lam trien dong — Tue, 26 Mar 2024 04:56:03 +0000

I use windows authentication but when the username didn't have permissions, I got a different error
`var sql = require('mssql/msnodesqlv8');

const config = {
user: 'sa',
password: 'Coffee',
server: 'localhost',
database: 'Cafe',
driver: 'msnodesqlv8',
port: 1433,
options: {
trustedConnection: true,
enableArithAbort: true
}

};

const conn = new sql.ConnectionPool(config).connect().then(pool => {
return pool;
});
`
When I connect to the internal server, I get an error:
ConnectionError: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
at PrivateConnection.callback2 (D:\NodeJS\node_modules\mssql\lib\msnodesqlv8\connection-pool.js:46:17)
at Immediate. (D:\NodeJS\node_modules\msnodesqlv8\lib\connection.js:41:14)
at process.processImmediate (node:internal/timers:478:21) {
code: undefined,
originalError: [Error: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified] {
sqlstate: 'IM002',
code: 0,
severity: 0,
serverName: '',
procName: '',
lineNumber: 0
}
}

React Native Login connect with sql server ?

Lam trien dong — Fri, 15 Mar 2024 03:47:49 +0000

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'

ERROR Cannot convert null value to object, Can you please fix my code errors ?

File: App.js
Code:
`//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 ?? l?u tr? thông tin ng??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 ng??i dùng nh?n nút Login
const handleLogin = async () => {

//console.log('login1');
try {
  // K?t n?i ??n c? 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 ?? l?y 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); // L?u 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);
      }
    );
  });

  // ?óng k?t n?i c? 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 ng??i dùng nh?n nút Signup
const handleSignup = async () => {
try {
//
} catch (error) {
console.error(error.message);
}
};

return (

  <View style={styles.list}>
    {/* Hi?n th? d? li?u trong ô l??i */}
    <FlatList
      data={sqliteData}
      renderItem={({ item }) => <Text>{JSON.stringify(item)}</Text>}
      keyExtractor={(_, index) => index.toString()}
    />
  </View>

  <View style={styles.inputText}>
    <View style={styles.text}>
     <View style={styles.user}>
     {/* H?p v?n b?n ?? ng??i dùng nh?p tên ng??i dùng */}
        <TextInput placeholder="Username" onChangeText={setUsername} />
     </View>
     <View style={styles.pass}>
        {/* H?p v?n b?n ?? ng??i dùng nh?p m?t kh?u */}
        <TextInput placeholder="Password" onChangeText={setPassword} secureTextEntry={true} />
     </View>
    </View>



    <View style={styles.button}>
      <View style={styles.login}>
          {/* Nút ?? th?c hi?n ch?c n?ng ??ng nh?p */}
          <Button title="Login" onPress={handleLogin} />
      </View>
      <View style={styles.signup}>
          {/* Nút ?? th?c hi?n ch?c n?ng ??ng ký */}
          <Button title="Signup" onPress={handleSignup} />
      </View>
    </View>
  </View>



</View>

);
};

export default App;

const styles = StyleSheet.create({
container: {
flex : 1,
backgroundColor : '#e7feff',

},
list: {

},
inputText : {
top: 340,

},
text : {
marginLeft : 30,
},

button : {
width : 360,
height : 150,
marginHorizontal : 20,
justifyContent : 'center',

},
login : {

signup : {
top : 20,

},

})`

File: server.js
Code:

`// 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: 'Coffee',
server: 'MICROSOFT',
database: 'Cafe',
};

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});
});`

See attached image file

DEV Community: Lam trien dong

When creating a react native project the app.js file can't be create ?

Connection fail to SQL Server using NodeJS mssql msnodesqlv8 from the server ?

React Native Login connect with sql server ?