JavaScript move next and previous, first, last record in sqlite database

[mohammed5]

I am new to javascript sqlite database. I have this code which open the database and retrieve rows. is there a functionality of moving to the
next and previous, first and last record. please help

const sqlite3 = require('sqlite3').verbose();

// open the database
let db = new sqlite3.Database('./mybook.db');
    console.error(err.message);

  console.log('Connected to the mybook database.');


db.serialize(() => {
  db.each(`SELECT questions as question,
                  wronganswer as wronganser
           FROM beginner`, (err, row) => {
    if (err) {
      console.error(err.message);
    }
    window.alert(row.no + "\t" + row.questions);
  });
});

db.close((err) => {
  if (err) {
    console.error(err.message);
  }
  console.log('Close the database connection.');
});

 

[phenomenon]

In JavaScript using SQLite, you can use the sqlite3 library. If you want to navigate through the records, you'll need to maintain some state about the current position in the result set. You can do this by fetching all the rows into an array or by using the LIMIT and OFFSET clauses in your SQL queries.

Here's an example of fetching all rows into an array and then navigating through them:

const sqlite3 = require('sqlite3').verbose();

// Open the database
let db = new sqlite3.Database('./mybook.db', (err) => {
  if (err) {
    console.error(err.message);
  }
  console.log('Connected to the mybook database.');
});

// Fetch all rows into an array
let rows = [];

db.serialize(() => {
  db.each(`SELECT questions as question,
                    wronganswer as wronganswer
           FROM beginner`, (err, row) => {
    if (err) {
      console.error(err.message);
    }
    rows.push(row);
  });
});

// Function to display the current row
function displayRow(index) {
  if (index >= 0 && index < rows.length) {
    const row = rows[index];
    window.alert(`${index + 1}\tQuestion: ${row.question}\nWrong Answer: ${row.wronganswer}`);
  } else {
    window.alert('No more records.');
  }
}

// Example: Display the first record
let currentIndex = 0;
displayRow(currentIndex);

// Example: Move to the next record
document.getElementById('nextButton').addEventListener('click', () => {
  currentIndex += 1;
  displayRow(currentIndex);
});

// Example: Move to the previous record
document.getElementById('prevButton').addEventListener('click', () => {
  currentIndex -= 1;
  displayRow(currentIndex);
});

// Close the database connection
db.close((err) => {
  if (err) {
    console.error(err.message);
  }
  console.log('Closed the database connection.');
});

In this example, the displayRow function is used to show the current row. The currentIndex variable keeps track of the current position in the rows array. The next and previous buttons are connected to event listeners that increment or decrement the currentIndex and then call displayRow to show the updated row.

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