crud.js

const sqlite3 = require('sqlite3').verbose();
exports.openDB = function(){
    return new sqlite3.Database('./test.db', sqlite3.OPEN_READWRITE, (err) => {
        if (err) {
          console.error(err.message);
        }
        console.log('Connected to the test database.');
      });
}

exports.serialize = function(db){
    return new Promise(function(resolve,reject){
        db.serialize(
            function(){
                let data = [];
                db.each(`SELECT ID as ID,
                    company as company,
                    name as name,
                    phone as phone,
                    email as email
                    FROM clients`, 
                (err, row) =>{
                    if (err) {
                        console.error(err.message);
                    }
                    data.push({
                        "ID":row.ID,
                        "company":row.company,
                        "name":row.name,
                        "phone":row.phone,
                        "email":row.email
                    });
                }, 
                () => {
                    resolve(data);
                });
                
            });
    });
}
exports.closeDB = function(db){
    db.close((err) => {
        if (err) {
          console.error(err.message);
        }
        console.log('Close the database connection.');
      });
}

exports.edit_client = function(db,data){
    db.run(`INSERT INTO clients (company, name, email, phone) VALUES(?,?,?,?)`, [data.company,data.name,data.email,data.phone], function(err) {
        if (err) {
          return console.log(err.message);
        }
        // get the last insert id
        console.log(`A row has been inserted with rowid ${this.lastID}`);
      });
}