quick and simple db cover for sqlite js

db.js

let sqlite3 = require('sqlite3').verbose();
let db = new sqlite3.Database('a.sqlite');

const user_table = {
    "id": "INTEGER primary key autoincrement",
    "email": "TEXT unique",
    "pw": "TEXT",
    "name": "TEXT",
    "teacher": "INTEGER"
}
const student_report_table = {
    "id": "INTEGER primary key",
    "grade": "INTEGER",
    "gpa": "INTEGER",
    "detailjson": "TEXT"
}

const pair_map = (k, s, v) => {
    let elements = [];
    if (k.length != v.length) return null;
    for (i = 0; i < k.length; i++)
        elements.push(k[i] + s + v[i]);
    return elements
}
const filled = (arr) => new Array(arr.length).fill("?");

function create_table(db, name, columns, dontcreateifexists = false) {
    let statement = "CREATE TABLE ";
    if (dontcreateifexists == true) statement += "IF NOT EXISTS "
    statement += (name + " (" + pair_map(Object.keys(columns), " ", Object.values(columns)).join(', ') + ");");
    db.run(statement, (err) => {
        if (err) return console.log(err.message);
        console.log("table " + name + " was created.")
    });
}
function insert(db, table, values) {
    const keys = Object.keys(values);
    db.run("INSERT INTO " + table + " (" + keys.join(', ') + ")" + " VALUES(" + filled(keys).join(', ') + ")", Object.values(values), (err) => {
        if (err) return console.log(err.message);
        console.log("table " + table + " insertion sucessful.")
    })
}
function update(db, table, values, condition_express, condition_values) {
    if(condition_express != "") condition_express = " WHERE "+condition_express;
    db.run("UPDATE " + table + " SET " + pair_map(Object.keys(values), "=", filled(values)) + condition_express, Object.values(values).concat(condition_values), (err) => {
        if (err) return console.log(err.message);
        console.log("table " + table + " update sucessful.")
    })
}
function select(db, table, columns, condition_express, condition_values) {
    if(condition_express != "") condition_express = " WHERE "+condition_express;
    db.all("SELECT "+columns.join(', ')+" FROM "+table+condition_express, condition_values, (err, rows) => {
        if (err) return console.log(err.message);
        console.log(rows)
    })
}
function delete_row(db, table, condition_express, condition_values) {
    db.run("DELETE FROM "+table+" WHERE "+condition_express, condition_values, (err) => {
        if (err) return console.log(err.message);
        console.log("table "+ table+" deleted "+condition_express+condition_values);
    })
}

function initialize_database() {
    db.serialize(() => {
        create_table(db, "User", user_table, true);
        create_table(db, "StudentReport", student_report_table, true);

        /* insert(db, "User", {
            "pw": "1234"
        })
        update(db, "User", {
            "pw":"4321",
        }, "pw=? AND id=1", [1234])
        delete_row(db, "User", "id=?", ["1"]);
        select(db, "User", ["pw"], "id=?", [2]);
        */
    });
    
    db.close();
}

module.exports = { initialize_database, insert, update, delete_row, select, db };