Database.js Example File

localstorage/localstorage/Database.js

  /****************************************************************************
  **
  ** Copyright (C) 2017 The Qt Company Ltd.
  ** Contact: https://www.qt.io/licensing/
  **
  ** This file is part of the documentation of the Qt Toolkit.
  **
  ** $QT_BEGIN_LICENSE:BSD$
  ** Commercial License Usage
  ** Licensees holding valid commercial Qt licenses may use this file in
  ** accordance with the commercial license agreement provided with the
  ** Software or, alternatively, in accordance with the terms contained in
  ** a written agreement between you and The Qt Company. For licensing terms
  ** and conditions see https://www.qt.io/terms-conditions. For further
  ** information use the contact form at https://www.qt.io/contact-us.
  **
  ** BSD License Usage
  ** Alternatively, you may use this file under the terms of the BSD license
  ** as follows:
  **
  ** "Redistribution and use in source and binary forms, with or without
  ** modification, are permitted provided that the following conditions are
  ** met:
  **   * Redistributions of source code must retain the above copyright
  **     notice, this list of conditions and the following disclaimer.
  **   * Redistributions in binary form must reproduce the above copyright
  **     notice, this list of conditions and the following disclaimer in
  **     the documentation and/or other materials provided with the
  **     distribution.
  **   * Neither the name of The Qt Company Ltd nor the names of its
  **     contributors may be used to endorse or promote products derived
  **     from this software without specific prior written permission.
  **
  **
  ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
  **
  ** $QT_END_LICENSE$
  **
  ****************************************************************************/

  function dbInit()
  {
      var db = LocalStorage.openDatabaseSync("Activity_Tracker_DB", "", "Track exercise", 1000000)
      try {
          db.transaction(function (tx) {
              tx.executeSql('CREATE TABLE IF NOT EXISTS trip_log (date text,trip_desc text,distance numeric)')
          })
      } catch (err) {
          console.log("Error creating table in database: " + err)
      };
  }

  function dbGetHandle()
  {
      try {
          var db = LocalStorage.openDatabaseSync("Activity_Tracker_DB", "",
                                                 "Track exercise", 1000000)
      } catch (err) {
          console.log("Error opening database: " + err)
      }
      return db
  }

  function dbInsert(Pdate, Pdesc, Pdistance)
  {
      var db = dbGetHandle()
      var rowid = 0;
      db.transaction(function (tx) {
          tx.executeSql('INSERT INTO trip_log VALUES(?, ?, ?)',
                        [Pdate, Pdesc, Pdistance])
          var result = tx.executeSql('SELECT last_insert_rowid()')
          rowid = result.insertId
      })
      return rowid;
  }

  function dbReadAll()
  {
      var db = dbGetHandle()
      db.transaction(function (tx) {
          var results = tx.executeSql(
                      'SELECT rowid,date,trip_desc,distance FROM trip_log order by rowid desc')
          for (var i = 0; i < results.rows.length; i++) {
              listModel.append({
                                   id: results.rows.item(i).rowid,
                                   checked: " ",
                                   date: results.rows.item(i).date,
                                   trip_desc: results.rows.item(i).trip_desc,
                                   distance: results.rows.item(i).distance
                               })
          }
      })
  }

  function dbUpdate(Pdate, Pdesc, Pdistance, Prowid)
  {
      var db = dbGetHandle()
      db.transaction(function (tx) {
          tx.executeSql(
                      'update trip_log set date=?, trip_desc=?, distance=? where rowid = ?', [Pdate, Pdesc, Pdistance, Prowid])
      })
  }

  function dbDeleteRow(Prowid)
  {
      var db = dbGetHandle()
      db.transaction(function (tx) {
          tx.executeSql('delete from trip_log where rowid = ?', [Prowid])
      })
  }