Sql Provider

sql.ts

import { Injectable } from '@angular/core';
import { SQLite } from '@ionic-native/sqlite';
import { Platform } from 'ionic-angular';
import { isEmpty, isNull, keys, sortBy, get, parseInt } from 'lodash';
import { browserDBInstance } from './browser';

declare var window: any;
const SQL_DB_NAME = process.env.IONIC_ENV === 'dev' ? '__broswer.db' : '__native.db';

@Injectable()
export class SqlProvider {

  dbInstance: any;

  constructor(public sqlite: SQLite, private platform: Platform) {
    this.init();
  }

  async init() {
    if (!this.platform.is('cordova')) {
      let db = window.openDatabase(SQL_DB_NAME, '1.0', 'DEV', 5 * 1024 * 1024);
      this.dbInstance = browserDBInstance(db);
    } else {
      this.dbInstance = await this.sqlite.create({
        name: SQL_DB_NAME,
        location: 'default'
      });
    }
  }
}

This setup was done on ionic 3. There are package changes in ionic 4. You might have to make some changes. Can you post exact error here?