bot-whatsapp/paquetes/base de datos/src/mysql/index.js

const mysql = require('mysql2')

class MyslAdapter {
    db
    listHistory = []
    credentials = { host: null, user: null, database: null, password: null }

    constructor(_credentials) {
        this.credentials = _credentials
        this.init().then()
    }

    async init() {
        this.db = mysql.createConnection(this.credentials)

        await this.db.connect(async (error) => {
            if (!error) {
                console.log(`Solicitud de conexión a base de datos exitosa`)
                await this.checkTableExists()
            }

            if (error) {
                console.log(`Solicitud de conexión fallida ${error.stack}`)
            }
        })
    }

    getPrevByNumber = (from) =>
        new Promise((resolve, reject) => {
            const sql = `SELECT * FROM history WHERE phone=${from} ORDER BY id DESC`
            this.db.query(sql, (error, rows) => {
                if (error) {
                    reject(error)
                }

                if (rows.length) {
                    const [row] = rows
                    row.options = JSON.parse(row.options)
                    resolve(row)
                }

                if (!rows.length) {
                    resolve(null)
                }
            })
        })

    save = (ctx) => {
        const values = [
            [
                ctx.ref,
                ctx.keyword,
                ctx.answer,
                ctx.refSerialize,
                ctx.from,
                JSON.stringify(ctx.options),
            ],
        ]
        const sql =
            'INSERT INTO history (ref, keyword, answer, refSerialize, phone, options ) values ?'

        this.db.query(sql, [values], (err) => {
            if (err) throw err
            console.log('Guardado en DB...', values)
        })
        this.listHistory.push(ctx)
    }

    createTable = () =>
        new Promise((resolve) => {
            const tableName = 'history'

         const sql = `CREATE TABLE ${tableName} 
            (id INT AUTO_INCREMENT PRIMARY KEY, 
            ref varchar(255) NOT NULL,
            keyword varchar(255) NOT NULL,
            answer longtext NOT NULL,
            refSerialize varchar(255) NOT NULL,
            phone varchar(255) NOT NULL,
            options longtext NOT NULL) 
            CHARACTER SET utf8mb4 COLLATE utf8mb4_General_ci`

            this.db.query(sql, (err) => {
                if (err) throw err
                console.log(`Tabla ${tableName} creada correctamente `)
                resolve(true)
            })
        })

    checkTableExists = () =>
        new Promise((resolve) => {
            const sql = "SHOW TABLES LIKE 'history'"

            this.db.query(sql, (err, rows) => {
                if (err) throw err

                if (!rows.length) {
                    this.createTable()
                }

                resolve(!!rows.length)
            })
        })
}

module.exports = MyslAdapter