Skip to content

litehelpers/cordova-sqlite-evmax-ext-workers-legacy-build-free

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Repository files navigation

Cordova/PhoneGap sqlite storage - evmax legacy workers - premium enterprise version with legacy support for web workers

Proof of concept test release with rudimentary support for web workers (Android/iOS/macOS ONLY).

Native interface to sqlite in a Cordova/PhoneGap plugin for Android and iOS with API similar to HTML5/Web SQL API.

This version is available under GPL v3 (http://www.gnu.org/licenses/gpl.txt) or commercial license and includes components available under the MIT and Apache 2.0 licenses listed in LICENSE.md. Contact for commercial license: sales@litehelpers.net

NOTE: Commercial licenses for Cordova-sqlite-enterprise-free purchased before July 2016 are valid for this plugin version. Commercial licenses for Cordova-sqlite-evplus purchased before November 2017 are valid for this plugin version. Commercial licenses for Cordova-sqlite-evcore versions are NOT valid for this plugin version. Commercial licenses for Cordova-sqlite-evplus purchased in November 2017 or later are NOT valid for this plugin version.

WARNINGS

DATA LOSS RISK WARNING IN MULTI-PAGE APPS

This plugin version suffers from a data loss risk in case of multi-page apps as discussed in litehelpers/Cordova-sqlite-storage#666. Workaround solution in cordova-sqlite-storage is problematic in this plugin version in case of access from both main and worker threads.

IMPORTANT API DEPRECATION NOTICE

The following API calls are now deprecated and may be removed at some point in the future (ref: litehelpers/cordova-sqlite-evplus-legacy-workers-free#5):

  • db.transaction()
  • db.readTransaction()
  • db.beginTransaction()

It is recommended to use the following calls instead:

  • db.executeSql() to read data or execute a single modification statement
  • db.sqlBatch() to execute a batch of modification statements within an ACID (atomic, failure-safe) transaction

MAY BE DEPRECATED IN THE FUTURE:

  • db.close() (not supported within web workers)
  • sqlitePlugin.deleteDatabase() (not supported within web workers)
  • non-default database location

WARNING: Multiple SQLite problem on Android

This plugin uses a non-standard Android-sqlite-connector implementation on Android. In case an application access the same database using multiple plugins there is a risk of data corruption ref: litehelpers/Cordova-sqlite-storage#626) as described in http://ericsink.com/entries/multiple_sqlite_problem.html and https://www.sqlite.org/howtocorrupt.html.

BREAKING CHANGE: Database location parameter is now mandatory

The location or iosDatabaseLocation MUST be specified in the openDatabase and deleteDatabase calls, as documented below.

IMPORTANT: iCloud backup of SQLite database is NOT allowed

As documented in the "A User’s iCloud Storage Is Limited" section of iCloudFundamentals in Mac Developer Library iCloud Design Guide (near the beginning):

  • DO store the following in iCloud:
    • [other items omitted]
    • Change log files for a SQLite database (a SQLite database’s store file must never be stored in iCloud)
  • DO NOT store the following in iCloud:
    • [items omitted]
- iCloudFundamentals in Mac Developer Library iCloud Design Guide

How to disable iCloud backup

Use the location or iosDatabaseLocation option in sqlitePlugin.openDatabase() to store the database in a subdirectory that is NOT backed up to iCloud, as described in the section below.

NOTE: Changing BackupWebStorage in config.xml has no effect on a database created by this plugin. BackupWebStorage applies only to local storage and/or Web SQL storage created in the WebView (not using this plugin). For reference: phonegap/build#338 (comment)

SECURITY TODO(s)

  • XHR URI request mechanism needs a secret code mechanism, like they have in the Cordova framework (only a security issue in case app loads external content)

Usage in web worker(s)

It is highly recommended to use the sample application www as a starting point, at least during initial testing.

Some important pointers:

  • See www/sample-index.html, the aqmain.js script must be included (or imported) before your app Javascript
  • See www/sample-index.js: a worker must be registered with a unique name with no special characters (TBD: specify which ones) using the AQ.aqregister function before the worker can have access to the sqlite plugin features
  • See www/sample-worker.js: some requirements in the worker script:
    • SQLitePlugin.js must be imported.
    • SQLitePlugin.js and aqworker.js must be in the same directory (SQLitePlugin.js automatically imports aqworker.js within a web worker).
    • To receive messages from the main thread, please use self.addEventListener instead of self.onmessage
    • This plugin sends internal string messages starting with !!! from the main thread to the worker thread. It is highly recommended to filter the messages for your own pattern.
    • Use sqlitePlugin.openDatabase instead of window.sqlitePlugin.openDatabase
  • www/SQLitePlugin.js is no longer automatically included in the main thread by Cordova.

iOS WKWebView NOTICE: Usage in web workers is NOT supported for iOS WKWebView ref: litehelpers/cordova-sqlite-evplus-legacy-workers-free#6.

LIMITATIONS and other TODO(s) to be fixed:

  • extra logging statements (almost completely commented out)
  • source code changes to the native Android and iOS versions needs some cleanup
  • not supported for iOS WKWebView ref: litehelpers/cordova-sqlite-evplus-legacy-workers-free#6
  • not possible to close or delete a database from a web worker

Status

  • Patches patches will NOT be accepted on this project due to some possible licensing issues.
  • Major modifications have been made to to support web workers
  • Certain features described below may be partially or completely broken
  • TBD ADDITIONAL TESTING NEEDED: Very large transaction in a web worker
  • Features omitted from this version branch: pre-populated database support; REGEXP extension for iOS; WP(7/8), Windows 8.1/Windows Phone 8.1/Windows 10, and Amazon Fire-OS support
  • Status for the other target platforms:
    • Android: now using Android-sqlite-connector (with sqlite 3.7.17), with support for FTS3/FTS4 and R-Tree
    • iOS/macOS: sqlite 3.8.10.2 embedded
  • A recent version of the Cordova CLI (such as 6.5.0 / 7.1.0) is recommended. (Cordova CLI 8.x includes cordova-android@7, NOT supported by this plugin version due to litehelpers/cordova-sqlite-evplus-legacy-workers-free#9.) Cordova versions older than 6.0.0 are missing the cordova-ios@4.0.0 security fixes. In addition it may be necessary to use cordova prepare in case of cordova-ios older than 4.3.0 (Cordova CLI 6.4.0).
  • This version uses a before_plugin_install hook to install sqlite3 library dependencies from cordova-sqlite-storage-dependencies via npm.
  • Build with SQLite (version 3.8.10.2) with the following build settings for iOS/macOS:
    • SQLITE_THREADSAFE=1
    • SQLITE_DEFAULT_MEMSTATUS=0
    • SQLITE_OMIT_DECLTYPE
    • SQLITE_OMIT_DEPRECATED
    • SQLITE_OMIT_PROGRESS_CALLBACK
    • SQLITE_OMIT_SHARED_CACHE
    • SQLITE_TEMP_STORE=2
    • SQLITE_OMIT_LOAD_EXTENSION
    • SQLITE_ENABLE_FTS3
    • SQLITE_ENABLE_FTS3_PARENTHESIS
    • SQLITE_ENABLE_FTS4
    • SQLITE_ENABLE_RTREE
    • SQLITE_DEFAULT_PAGE_SIZE=1024 and SQLITE_DEFAULT_CACHE_SIZE=2000 to avoid "potentially distruptive change(s)" from SQLite 3.12.0 ref: http://sqlite.org/pgszchng2016.html
  • Use of other systems such as Cordova Plugman, PhoneGap CLI, PhoneGap Build, and Intel XDK is no longer supported since they do not honor the before_plugin_install hook. The supported solution is to use litehelpers / Cordova-sqlite-evcore-extbuild-free (available with GPL or commercial license terms) or litehelpers / Cordova-sqlite-legacy-build-support (limited testing, limited updates)
  • The iOS database location is now mandatory, as documented below.
  • This version supports the use of two (2) possible following Android sqlite database implementation:
    • default: lightweight Android-sqlite-connector
    • optional: built-in Android database classes (usage described below) (NOT supported in this verison branch)
  • The following features are available in litehelpers / cordova-sqlite-ext (WITHOUT worker support):
    • REGEXP (Android/iOS/macOS)
    • SELECT BLOB data in Base64 format (all platforms Android/iOS/macOS/Windows)
    • Pre-populated database (Android/iOS/macOS/Windows)
  • FTS3, FTS4, and R-Tree are tested working OK in this version branch (for all target platforms in this version branch Android/iOS/macOS)
  • Android older than 5.0 NOT supported for web workers
  • iOS versions supported: 8.x / 9.x / 10.x / 11.x

Announcements

Highlights

  • Drop-in replacement for HTML5/Web SQL API: the only change should be to replace the static window.openDatabase() factory call with window.sqlitePlugin.openDatabase(), with parameters as documented below.
  • Failure-safe nested transactions with batch processing optimizations (according to HTML5/Web SQL API)
  • API (based on HTML5/Web SQL API) is designed to be as flexible as possible but does not allow the application to leave any transactions hanging open.
  • As described in this posting:
    • Keeps sqlite database in a user data location that is known; can be reconfigured (iOS/macOS platform version); and may be synchronized to iCloud (iOS platform version).
    • No 5MB maximum, more information at: http://www.sqlite.org/limits.html
  • Also tested for multi-page applications with window location changes
  • This project is self-contained (with sqlite3 dependencies auto-fetched by npm); no dependencies on other plugins such as cordova-plugin-file
  • SQLCipher support for Android/iOS/macOS/Windows is available (WITHOUT worker support) in: litehelpers / Cordova-sqlcipher-adapter
  • Intellectual property:
    • All source code is tracked to the original author in git
    • Major authors are tracked in AUTHORS.md
    • License of each component is tracked in LICENSE.md
    • History of this project is also described in HISTORY.md

TIP: It is possible to migrate from Cordova to a pure native solution and continue using the data stored by this plugin.

Some apps using this plugin

TBD

Some known deviations from the Web SQL database standard

  • The window.sqlitePlugin.openDatabase static factory call takes a different set of parameters than the standard Web SQL window.openDatabase static factory call. In case you have to use existing Web SQL code with no modifications please see the Web SQL replacement tip below.
  • This plugin does not support the database creation callback or standard database versions. Please read the Database schema versions section below for tips on how to support database schema versioning.
  • This plugin does not support the synchronous Web SQL interfaces.
  • Error reporting is not 100% compliant, with some issues described below.
  • In case of a transaction with an sql statement error for which there is no error handler, the error handler does not return false, or the error handler throws an exception, the plugin will fire more sql statement callbacks before the transaction is aborted with ROLLBACK.
  • This plugin supports some non-standard features as described below.

Security

Security of sensitive data

According to Web SQL Database API 7.2 Sensitivity of data:

User agents should treat persistently stored data as potentially sensitive; it's quite possible for e-mails, calendar appointments, health records, or other confidential documents to be stored in this mechanism.

To this end, user agents should ensure that when deleting data, it is promptly deleted from the underlying storage.

Unfortunately this plugin will not actually overwrite the deleted content unless the secure_delete PRAGMA is used.

SQL injection

As "strongly recommended" by Web SQL Database API 8.5 SQL injection:

Authors are strongly recommended to make use of the ? placeholder feature of the executeSql() method, and to never construct SQL statements on the fly.

Avoiding data loss

  • Double-check that the application code follows the documented API for SQL statements, parameter values, success callbacks, and error callbacks.
  • For standard Web SQL transactions include a transaction error callback with the proper logic that indicates to the user if data cannot be stored for any reason. In case of individual SQL error handlers be sure to indicate to the user if there is any issue with storing data.
  • For single statement and batch transactions include an error callback with logic that indicates to the user if data cannot be stored for any reason.

Known issues

  • POSSIBLE TRANSACTION ISSUE IN MULTI-PAGE APP WITH POSSIBLE DATA LOSS ref: litehelpers/Cordova-sqlite-storage#666
  • iOS/macOS platform version does not support certain rapidly repeated open-and-close or open-and-delete test scenarios due to how the implementation handles background processing
  • As described below, auto-vacuum is NOT enabled by default.
  • It is possible to request a SQL statement list such as "SELECT 1; SELECT 2" within a single SQL statement string, however the plugin will only execute the first statement and silently ignore the others ref: litehelpers/Cordova-sqlite-storage#551
  • INSERT statement that affects multiple rows (due to SELECT cause or using TRIGGER(s), for example) does not report proper rowsAffected on Android
  • Memory issue observed when adding super extreme large number of records on Android due to the JSON implementation which is improved in litehelpers / Cordova-sqlite-evcore-extbuild-free (GPL or commercial license terms)
  • Infinity (positive or negative) values are not supported on Android/iOS/macOS due to issues described above including a possible crash on iOS/macOS ref: litehelpers/Cordova-sqlite-storage#405
  • A stability issue was reported on the iOS version when in use together with SockJS client such as pusher-js at the same time (see litehelpers/Cordova-sqlite-storage#196). The workaround is to call sqlite functions and SockJS client functions in separate ticks (using setTimeout with 0 timeout).
  • If a sql statement fails for which there is no error handler or the error handler does not return false to signal transaction recovery, the plugin fires the remaining sql callbacks before aborting the transaction.
  • In case of an error, the error code member is bogus on Android.
  • Possible crash on Android when using Unicode emoji and other 4-octet UTF-8 characters due to Android bug 81341, which should be fixed in Android 6.x
  • Close/delete database bugs described below.
  • When a database is opened and deleted without closing, the iOS/macOS platform version is known to leak resources.
  • It is NOT possible to open multiple databases with the same name but in different locations (iOS/macOS platform version).
  • Incorrect or missing insertId/rowsAffected in results for INSERT/UPDATE/DELETE SQL statements with extra semicolon(s) in the beginning for Android (android.database implementation)
  • readTransaction does not reject modification SQL statements with extra semicolon(s) in the beginning
  • Problems reported with PhoneGap Build in the past:

Issues fixed in some newer version branches:

  • In case of an error, the error code member is bogus on Android
  • iOS platform version generates extra logging in release version
  • iOS platform version may crash if deleteDatabase is called with an object in place of the database name
  • readTransaction does not reject ALTER, REINDEX, and REPLACE operations
  • readTransaction does not reject modification statements with extra semicolon(s) in the beginning
  • extra executeSql callbacks triggered in a transaction after a failure that was not recovered by an error callback that returns false
  • does not signal an error in case of excess parameter argument values given on iOS/macOS

Other limitations

  • The db version, display name, and size parameter values are not supported and will be ignored. (No longer supported by the API)
  • Absolute and relative subdirectory path(s) are not tested or supported.
  • This plugin will not work before the callback for the 'deviceready' event has been fired, as described in Usage. (This is consistent with the other Cordova plugins.)
  • Super extreme large records are not supported by this plugin version. TBD: specify maximum record; FUTURE TBD: to be further tested in litehelpers / Cordova-sqlite-evcore-extbuild-free (GPL or commercial license terms).
  • In-memory database db=window.sqlitePlugin.openDatabase({name: ':memory:', ...}) is currently not supported.
  • The Android version cannot work with more than 100 open db files (due to the threading model used).
  • UNICODE \u2028 (line separator) and \u2029 (paragraph separator) characters are not supported and known to be broken on iOS, macOS, and Android platforms due to JSON issues reported in Cordova bug CB-9435 and cordova/cordova-discuss#57. There may be a similar issue with certain other UNICODE characters in the iOS/macOS version (needs further investigation). This is fixed for iOS in litehelpers / cordova-sqlite-evplus-ext-legacy-build-free and litehelpers / Cordova-sqlite-evplus-legacy-attach-detach-free (GPL or special commercial license terms) as well as litehelpers / cordova-sqlite-evmax-ext-workers-legacy-build-free (GPL or premium commercial license terms).
  • The BLOB data type is not fully supported by this version branch. SELECT BLOB in Base64 format is supported by litehelpers / cordova-sqlite-ext (permissive license terms) and litehelpers / Cordova-sqlite-evcore-extbuild-free (GPL or commercial license terms).
  • Truncation in case of UNICODE \u0000 (same as \0) character on Android.
  • Case-insensitive matching and other string manipulations on Unicode characters, which is provided by optional ICU integration in the sqlite source and working with recent versions of Android, is not supported for any target platforms.
  • iOS/macOS platform version uses a thread pool but with only one thread working at a time due to "synchronized" database access
  • Some large query results may be slow, also due to the JSON implementation.
  • ATTACH to another database file is not supported by this version branch. Attach/detach is supported (along with the memory and iOS UNICODE \u2028 line separator / \u2029 paragraph separator fixes) in litehelpers / Cordova-sqlite-evplus-legacy-attach-detach-free (available with GPL or special commercial license terms).
  • UPDATE/DELETE with LIMIT or ORDER BY is not supported.
  • WITH clause is not supported by some older Android/iOS versions.
  • User-defined savepoints are not supported and not expected to be compatible with the transaction locking mechanism used by this plugin. In addition, the use of BEGIN/COMMIT/ROLLBACK statements is not supported.
  • Problems have been reported when using this plugin with Crosswalk (for Android). It may help to install Crosswalk as a plugin instead of using Crosswalk to create the project.
  • Does not work with axemclion / react-native-cordova-plugin since the window.sqlitePlugin object is not properly exported (ES5 feature). It is recommended to use andpor / react-native-sqlite-storage for SQLite database access with React Native Android/iOS instead.

Further testing needed

  • Integration with PhoneGap developer app
  • Use within InAppBrowser
  • Use within an iframe (see litehelpers/Cordova-sqlite-storage#368 (comment))
  • Date/time handling
  • Maximum record size supported
  • Actual behavior when using SAVEPOINT(s)
  • R-Tree is not fully tested with Android
  • UNICODE characters not fully tested
  • Use with TRIGGER(s), JOIN and ORDER BY RANDOM
  • UPDATE/DELETE with LIMIT or ORDER BY (newer Android/iOS versions)
  • Integration with JXCore for Cordova (must be built without sqlite(3) built-in)
  • Delete an open database inside a statement or transaction callback.
  • WITH clause (not supported by some older sqlite3 versions)
  • Handling of invalid transaction and transaction.executeSql arguments
  • Use of database locations on macOS
  • Extremely large and small INTEGER and REAL values ref: litehelpers/Cordova-sqlite-storage#627)
  • More emojis and other 4-octet UTF-8 characters
  • ?NNN/:AAA/@AAAA/$AAAA parameter placeholders ref: https://www.sqlite.org/lang_expr.html#varparam, https://www.sqlite.org/c3ref/bind_blob.html)
  • Single-statement and SQL batch transaction calls with invalid arguments (TBD behavior subject to change)

Some tips and tricks

  • If you run into problems and your code follows the asynchronous HTML5/Web SQL transaction API, you can try opening a test database using window.openDatabase and see if you get the same problems.
  • In case your database schema may change, it is recommended to keep a table with one row and one column to keep track of your own schema version number. It is possible to add it later. The recommended schema update procedure is described below.

Pitfalls

Some common pitfall(s)

  • If a database is opened using the standard window.openDatabase call it will not have any of the benefits of this plugin and features such as the sqlBatch call would not be available.
  • It is NOT allowed to execute sql statements on a transaction that has already finished, as described below. This is consistent with the HTML5/Web SQL API.
  • The plugin class name starts with "SQL" in capital letters, but in Javascript the sqlitePlugin object name starts with "sql" in small letters.
  • Attempting to open a database before receiving the 'deviceready' event callback.
  • Inserting STRING into ID field
  • Auto-vacuum is NOT enabled by default. It is recommended to periodically VACUUM the database.
  • Transactions on a database are run sequentially. A large transaction could block smaller transactions requested afterwards.

Some weird pitfall(s)

Angular/ngCordova/Ionic-related pitfalls

General Cordova pitfalls

Documented in: brodybits / Avoiding-some-Cordova-pitfalls

Major TODOs

  • Integrate with IndexedDBShim and some other libraries such as Sequelize, Squel.js, WebSqlSync, Persistence.js, Knex, etc.

For future considertion

  • Auto-vacuum option
  • Browser platform

Alternatives

Comparison of sqlite plugin versions

Other SQLite adapter projects

Alternative solutions

Usage

Self-test functions

To verify that both the Javascript and native part of this plugin are installed in your application:

window.sqlitePlugin.echoTest(successCallback, errorCallback);

To verify that this plugin is able to open, populate, read, update, and delete a test database (named ___$$$___litehelpers___$$$___test___$$$___.db) properly:

window.sqlitePlugin.selfTest(successCallback, errorCallback);

IMPORTANT: Please wait for the 'deviceready' event (see below for an example).

General

  • Drop-in replacement for HTML5/Web SQL API: the only change should be to replace the static window.openDatabase() factory call with window.sqlitePlugin.openDatabase(), with parameters as documented below. (Some known deviations are documented in newer version branches.)
  • Single-page application design is recommended.
  • In case of a multi-page application the JavaScript used by each page must use sqlitePlugin.openDatabase to open the database access handle object before it can access the data.

NOTE: If a sqlite statement in a transaction fails with an error, the error handler must return false in order to recover the transaction. This is correct according to the HTML5/Web SQL API standard. This is different from the WebKit implementation of Web SQL in Android and iOS which recovers the transaction if a sql error hander returns a non-true value.

Opening a database

To open a database access handle object (in the new default location):

var db = window.sqlitePlugin.openDatabase({name: 'my.db', location: 'default'}, successcb, errorcb);

WARNING: The new "default" location value is NOT the same as the old default location and would break an upgrade for an app that was using the old default value (0) on iOS.

WARNING 2: As described above: by default this plugin uses a non-standard Android-sqlite-connector implementation on Android. In case an application access the same database using multiple plugins there is a risk of data corruption ref: litehelpers/Cordova-sqlite-storage#626) as described in http://ericsink.com/entries/multiple_sqlite_problem.html and https://www.sqlite.org/howtocorrupt.html.

MAY BE DEPRECATED IN THE FUTURE: To specify a different location (affects iOS only):

var db = window.sqlitePlugin.openDatabase({name: 'my.db', iosDatabaseLocation: 'Library'}, successcb, errorcb);

where the iosDatabaseLocation option may be set to one of the following choices:

  • default: Library/LocalDatabase subdirectory - NOT visible to iTunes and NOT backed up by iCloud
  • Library: Library subdirectory - backed up by iCloud, NOT visible to iTunes
  • Documents: Documents subdirectory - visible to iTunes and backed up by iCloud

WARNING: Again, the new "default" iosDatabaseLocation value is NOT the same as the old default location and would break an upgrade for an app using the old default value (0) on iOS.

ALTERNATIVE (deprecated, may be removed from a future version):

  • var db = window.sqlitePlugin.openDatabase({name: "my.db", location: 1}, successcb, errorcb);

with the location option set to one the following choices (affects iOS only):

  • 0 (default): Documents - visible to iTunes and backed up by iCloud
  • 1: Library - backed up by iCloud, NOT visible to iTunes
  • 2: Library/LocalDatabase - NOT visible to iTunes and NOT backed up by iCloud (same as using "default")

No longer supported (see tip below to overwrite window.openDatabase): var db = window.sqlitePlugin.openDatabase("myDatabase.db", "1.0", "Demo", -1);

IMPORTANT: Please wait for the 'deviceready' event, as in the following example:

// Wait for Cordova to load
document.addEventListener('deviceready', onDeviceReady, false);

// Cordova is ready
function onDeviceReady() {
  var db = window.sqlitePlugin.openDatabase({name: 'my.db', location: 'default'});
  // ...
}

The successcb and errorcb callback parameters are optional but can be extremely helpful in case anything goes wrong. For example:

window.sqlitePlugin.openDatabase({name: 'my.db', location: 'default'}, function(db) {
  db.transaction(function(tx) {
    // ...
  }, function(err) {
    console.log('Open database ERROR: ' + JSON.stringify(err));
  });
});

If any sql statements or transactions are attempted on a database object before the openDatabase result is known, they will be queued and will be aborted in case the database cannot be opened.

DATABASE NAME NOTES:

  • Database file names with slash (/) character(s) are not supported and not expected to work.
  • Database file names with emojis and other 4-octet UTF-8 characters are NOT RECOMMENDED.

OTHER NOTES:

  • The database file name should include the extension, if desired.
  • It is possible to open multiple database access handle objects for the same database.
  • The database handle access object can be closed as described below.

Web SQL replacement tip:

To overwrite window.openDatabase:

window.openDatabase = function(dbname, ignored1, ignored2, ignored3) {
  return window.sqlitePlugin.openDatabase({name: dbname, location: 'default'});
};

SQL transactions

The following types of SQL transactions are supported by this version:

  • Single-statement transactions
  • SQL batch transactions

DEPRECATED, may be removed from this plugin version in the near future:

  • Standard asynchronous transactions
  • Multi-part transactions

NOTE: Transaction requests are kept in one queue per database and executed in sequential order, according to the HTML5/Web SQL API.

WARNING: It is possible to request a SQL statement list such as "SELECT 1; SELECT 2" within a single SQL statement string, however the plugin will only execute the first statement and silently ignore the others. This could result in data loss if such a SQL statement list with any INSERT or UPDATE statement(s) are included. For reference: litehelpers/Cordova-sqlite-storage#551

Single-statement transactions

Sample with INSERT:

db.executeSql('INSERT INTO MyTable VALUES (?)', ['test-value'], function (resultSet) {
  console.log('resultSet.insertId: ' + resultSet.insertId);
  console.log('resultSet.rowsAffected: ' + resultSet.rowsAffected);
}, function(error) {
  console.log('SELECT error: ' + error.message);
});

Sample with SELECT:

db.executeSql("SELECT LENGTH('tenletters') AS stringlength", [], function (resultSet) {
  console.log('got stringlength: ' + resultSet.rows.item(0).stringlength);
}, function(error) {
  console.log('SELECT error: ' + error.message);
});

NOTE/minor bug: The object returned by resultSet.rows.item(rowNumber) is not immutable. In addition, multiple calls to resultSet.rows.item(rowNumber) with the same rowNumber on the same resultSet object return the same object. For example, the following code will show Second uppertext result: ANOTHER:

db.executeSql("SELECT UPPER('First') AS uppertext", [], function (resultSet) {
  var obj1 = resultSet.rows.item(0);
  obj1.uppertext = 'ANOTHER';
  console.log('Second uppertext result: ' + resultSet.rows.item(0).uppertext);
  console.log('SELECT error: ' + error.message);
});

SQL batch transactions

Sample:

db.sqlBatch([
  'DROP TABLE IF EXISTS MyTable',
  'CREATE TABLE MyTable (SampleColumn)',
  [ 'INSERT INTO MyTable VALUES (?)', ['test-value'] ],
], function() {
  db.executeSql('SELECT * FROM MyTable', [], function (resultSet) {
    console.log('Sample column value: ' + resultSet.rows.item(0).SampleColumn);
  });
}, function(error) {
  console.log('Populate table error: ' + error.message);
});

In case of an error, all changes in a sql batch are automatically discarded using ROLLBACK.

Standard asynchronous transactions

NOTICE: This API call is deprecated and may be removed in the near future ref: litehelpers / cordova-sqlite-evplus-legacy-workers-free#5.

Standard asynchronous transactions follow the HTML5/Web SQL API which is very well documented and uses BEGIN and COMMIT or ROLLBACK to keep the transactions failure-safe. Here is a simple example:

db.transaction(function(tx) {
  tx.executeSql('DROP TABLE IF EXISTS MyTable');
  tx.executeSql('CREATE TABLE MyTable (SampleColumn)');
  tx.executeSql('INSERT INTO MyTable VALUES (?)', ['test-value'], function(tx, resultSet) {
    console.log('resultSet.insertId: ' + resultSet.insertId);
    console.log('resultSet.rowsAffected: ' + resultSet.rowsAffected);
  }, function(tx, error) {
    console.log('INSERT error: ' + error.message);
  });
}, function(error) {
  console.log('transaction error: ' + error.message);
}, function() {
  console.log('transaction ok');
});

In case of a read-only transaction, it is possible to use readTransaction which will not use BEGIN, COMMIT, or ROLLBACK:

db.readTransaction(function(tx) {
  tx.executeSql("SELECT UPPER('Some US-ASCII text') AS uppertext", [], function(tx, resultSet) {
    console.log("resultSet.rows.item(0).uppertext: " + resultSet.rows.item(0).uppertext);
  }, function(tx, error) {
    console.log('SELECT error: ' + error.message);
  });
}, function(error) {
  console.log('transaction error: ' + error.message);
}, function() {
  console.log('transaction ok');
});

NOTICE: The tx.executeSql success and error callbacks should take two parameters (first parameter for the transaction object). This is different from the single-statement success and error callbacks described above.

WARNING: It is NOT allowed to execute sql statements on a transaction after it has finished. Here is an example from the Populating Cordova SQLite storage with the JQuery API post at http://www.brodybits.com/cordova/sqlite/api/jquery/2015/10/26/populating-cordova-sqlite-storage-with-the-jquery-api.html:

  // BROKEN SAMPLE:
  db.executeSql("DROP TABLE IF EXISTS tt");
  db.executeSql("CREATE TABLE tt (data)");

  db.transaction(function(tx) {
    $.ajax({
      url: 'https://api.github.com/users/litehelpers/repos',
      dataType: 'json',
      success: function(res) {
        console.log('Got AJAX response: ' + JSON.stringify(res));
        $.each(res, function(i, item) {
          console.log('REPO NAME: ' + item.name);
          tx.executeSql("INSERT INTO tt values (?)", JSON.stringify(item.name));
        });
      }
    });
  }, function(e) {
    console.log('Transaction error: ' + e.message);
  }, function() {
    // Check results:
    db.executeSql('SELECT COUNT(*) FROM tt', [], function(res) {
      console.log('Check SELECT result: ' + JSON.stringify(res.rows.item(0)));
    });
  });

You can find more details and a step-by-step description how to do this right in the Populating Cordova SQLite storage with the JQuery API post at: http://www.brodybits.com/cordova/sqlite/api/jquery/2015/10/26/populating-cordova-sqlite-storage-with-the-jquery-api.html

NOTE/minor bug: Just like the single-statement transaction described above, the object returned by resultSet.rows.item(rowNumber) is not immutable. In addition, multiple calls to resultSet.rows.item(rowNumber) with the same rowNumber on the same resultSet object return the same object. For example, the following code will show Second uppertext result: ANOTHER:

db.readTransaction(function(tx) {
  tx.executeSql("SELECT UPPER('First') AS uppertext", [], function(tx, resultSet) {
    var obj1 = resultSet.rows.item(0);
    obj1.uppertext = 'ANOTHER';
    console.log('Second uppertext result: ' + resultSet.rows.item(0).uppertext);
    console.log('SELECT error: ' + error.message);
  });
});

FUTURE TBD: It should be possible to get a row result object using resultSet.rows[rowNumber], also in case of a single-statement transaction. This is non-standard but is supported by the Chrome desktop browser.

Multi-part transactions

NOTICE: This API call is deprecated and may be removed in the near future ref: litehelpers / cordova-sqlite-evplus-legacy-workers-free#5.

Sample (with success and error callbacks):

var tx = db.beginTransaction();
tx.executeSql("DROP TABLE IF EXISTS mytable");
tx.executeSql("CREATE TABLE mytable (myfield)");

tx.executeSql("INSERT INTO mytable values(?)", ['test value']);
tx.executeSql("SELECT * from mytable", [], function(tx, res) {
  console.log("Got value: " + res.rows.item(0).myfield);
}, function(tx, e) {
  console.log("Ignore unexpected error callback with message: " + e.message);
  return false;
});

tx.end(function() {
  console.log('Optional success callback fired');
}, function(e) {
  console.log("Optional error callback fired with message: " + e.message);
});

Sample with abort:

var tx = db.beginTransaction();
tx.executeSql("INSERT INTO mytable values(?)", ['wrong data']);
tx.abort(function() {
  console.log('Optional callback');
});

IMPORTANT NOTES:

  • In case a tx.executeSql call results in an error and it does not have an error callback or the error callback does NOT return false, the transaction will be aborted immediately with a ROLLBACK upon the tx.end call.
  • BUG: If a tx.executeSql call results in an error for which there is no error callback, the error callback does NOT return false, or the error callback throws an exception, the transaction is silently aborted and no tx.end callbacks will be fired.
  • When a multi-part transaction is started by the db.beginTransaction call, all other transactions are blocked until the multi-part transaction is either completed successfully or aborted (with a ROLLBACK).

Background processing

The threading model depends on which version is used:

  • For Android, one background thread per db;
  • for iOS/macOS, background processing using a very limited thread pool (only one thread working at a time).

Sample with PRAGMA feature

Creates a table, adds a single entry, then queries the count to check if the item was inserted as expected. Note that a new transaction is created in the middle of the first callback.

// Wait for Cordova to load
document.addEventListener('deviceready', onDeviceReady, false);

// Cordova is ready
function onDeviceReady() {
  var db = window.sqlitePlugin.openDatabase({name: 'my.db', location: 'default'});

  db.transaction(function(tx) {
    tx.executeSql('DROP TABLE IF EXISTS test_table');
    tx.executeSql('CREATE TABLE IF NOT EXISTS test_table (id integer primary key, data text, data_num integer)');

    // demonstrate PRAGMA:
    db.executeSql("pragma table_info (test_table);", [], function(res) {
      console.log("PRAGMA res: " + JSON.stringify(res));
    });

    tx.executeSql("INSERT INTO test_table (data, data_num) VALUES (?,?)", ["test", 100], function(tx, res) {
      console.log("insertId: " + res.insertId + " -- probably 1");
      console.log("rowsAffected: " + res.rowsAffected + " -- should be 1");

      db.transaction(function(tx) {
        tx.executeSql("select count(id) as cnt from test_table;", [], function(tx, res) {
          console.log("res.rows.length: " + res.rows.length + " -- should be 1");
          console.log("res.rows.item(0).cnt: " + res.rows.item(0).cnt + " -- should be 1");
        });
      });

    }, function(e) {
      console.log("ERROR: " + e.message);
    });
  });
}

NOTE: PRAGMA statements must be executed in executeSql() on the database object (i.e. db.executeSql()) and NOT within a transaction.

Sample with transaction-level nesting

In this case, the same transaction in the first executeSql() callback is being reused to run executeSql() again.

// Wait for Cordova to load
document.addEventListener('deviceready', onDeviceReady, false);

// Cordova is ready
function onDeviceReady() {
  var db = window.sqlitePlugin.openDatabase({name: 'my.db', location: 'default'});

  db.transaction(function(tx) {
    tx.executeSql('DROP TABLE IF EXISTS test_table');
    tx.executeSql('CREATE TABLE IF NOT EXISTS test_table (id integer primary key, data text, data_num integer)');

    tx.executeSql("INSERT INTO test_table (data, data_num) VALUES (?,?)", ["test", 100], function(tx, res) {
      console.log("insertId: " + res.insertId + " -- probably 1");
      console.log("rowsAffected: " + res.rowsAffected + " -- should be 1");

      tx.executeSql("select count(id) as cnt from test_table;", [], function(tx, res) {
        console.log("res.rows.length: " + res.rows.length + " -- should be 1");
        console.log("res.rows.item(0).cnt: " + res.rows.item(0).cnt + " -- should be 1");
      });

    }, function(tx, e) {
      console.log("ERROR: " + e.message);
    });
  });
}

This case will also works with Safari (WebKit), assuming you replace window.sqlitePlugin.openDatabase with window.openDatabase.

Close a database object

DEPRECATED and subject to removal from this plugin version:

This will invalidate all handle access handle objects for the database that is closed:

db.close(successcb, errorcb);

It is OK to close the database within a transaction callback but NOT within a statement callback. The following example is OK:

db.transaction(function(tx) {
  tx.executeSql("SELECT LENGTH('tenletters') AS stringlength", [], function(tx, res) {
    console.log('got stringlength: ' + res.rows.item(0).stringlength);
  });
}, function(error) {
  // OK to close here:
  console.log('transaction error: ' + error.message);
  db.close();
}, function() {
  // OK to close here:
  console.log('transaction ok');
  db.close(function() {
    console.log('database is closed ok');
  });
});

The following example is NOT OK:

// BROKEN:
db.transaction(function(tx) {
  tx.executeSql("SELECT LENGTH('tenletters') AS stringlength", [], function(tx, res) {
    console.log('got stringlength: ' + res.rows.item(0).stringlength);
    // BROKEN - this will trigger the error callback:
    db.close(function() {
      console.log('database is closed ok');
    }, function(error) {
      console.log('ERROR closing database');
    });
  });
});

BUG: It is currently NOT possible to close a database in a db.executeSql callback. For example:

// BROKEN DUE TO BUG:
db.executeSql("SELECT LENGTH('tenletters') AS stringlength", [], function (res) {
  var stringlength = res.rows.item(0).stringlength;
  console.log('got stringlength: ' + res.rows.item(0).stringlength);

  // BROKEN - this will trigger the error callback DUE TO BUG:
  db.close(function() {
    console.log('database is closed ok');
  }, function(error) {
    console.log('ERROR closing database');
  });
});

SECOND BUG: When a database connection is closed, any queued transactions are left hanging. All pending transactions should be errored when a database connection is closed.

NOTE: As described above, if multiple database access handle objects are opened for the same database and one database handle access object is closed, the database is no longer available for the other database handle objects. Possible workarounds:

  • It is still possible to open one or more new database handle objects on a database that has been closed.
  • It should be OK not to explicitly close a database handle since database transactions are ACID compliant and the app's memory resources are cleaned up by the system upon termination.

FUTURE TBD: dispose method on the database access handle object, such that a database is closed once all access handle objects are disposed.

Delete a database

DEPRECATED and subject to removal from this plugin version:

window.sqlitePlugin.deleteDatabase({name: 'my.db', location: 'default'}, successcb, errorcb);

with location or iosDatabaseLocation parameter required as described above for openDatabase (affects iOS/macOS only)

BUG: When a database is deleted, any queued transactions for that database are left hanging. TODO: All pending transactions should be errored when a database is deleted.

Database schema versions

The transactional nature of the API makes it relatively straightforward to manage a database schema that may be upgraded over time (adding new columns or new tables, for example). Here is the recommended procedure to follow upon app startup:

  • Check your database schema version number (you can use db.executeSql since it should be a very simple query)
  • If your database needs to be upgraded, do the following within a single transaction to be failure-safe:

IMPORTANT: Since we cannot be certain when the users will actually update their apps, old schema versions will have to be supported for a very long time.

Use with Ionic/ngCordova/Angular

Ionic 2

Tutorials with Ionic 2:

Sample for Ionic 2 wanted ref: litehelpers/Cordova-sqlite-storage#585

Ionic 1

Tutorial with Ionic 1: https://blog.nraboy.com/2014/11/use-sqlite-instead-local-storage-ionic-framework/

A sample for Ionic 1 is provided at: litehelpers / Ionic-sqlite-database-example

Documentation at: http://ngcordova.com/docs/plugins/sqlite/

Other resource (apparently for Ionic 1): https://www.packtpub.com/books/content/how-use-sqlite-ionic-store-data

NOTE: Some Ionic and other Angular pitfalls are described above.

Installing

Easy install with Cordova CLI tool

npm install -g cordova # (in case you don't have cordova)
cordova create MyProjectFolder com.my.project MyProject && cd MyProjectFolder # if you are just starting
cordova plugin add https://github.com/litehelpers/cordova-sqlite-evplus-legacy-workers-free

CLI NOTES:

  • You may have to update the platform and plugin version(s) before you can build: cordova prepare (or for a specific platform such as iOS: cordova prepare ios)
  • If you cannot build for a platform after cordova prepare, you may have to remove the platform and add it again, such as:
cordova platform rm ios
cordova platform add ios

or more drastically:

rm -rf platforms
cordova platform add ios

Source tree

  • SQLitePlugin.coffee.md: platform-independent (Literate coffee-script, can be read by recent coffee-script compiler)
  • src: platform-specific source code:
    • common - sqlite implementation (sqlite3.[hc]) for iOS/macOS
    • android - Java plugin code for Android
    • ios - Objective-C plugin code for iOS/macOS
    • www - SQLitePluginHelper.js to provide Cordova exec access for SQLitePlugin.js
  • sample-worker: Sample application with web workers support integrated as described above
  • spec: test suite using Jasmine (2.2.0), ported from QUnit test-www test suite, working on all platforms
  • tests: very simple Jasmine test suite that is run on Circle CI (Android version) and Travis CI (iOS version)
  • www: SQLitePlugin.js platform-independent Javascript as generated from SQLitePlugin.coffee.md (and checked in!)

Installation test

Easy installation test

Use window.sqlitePlugin.echoTest and/or window.sqlitePlugin.selfTest as described above (please wait for the deviceready event).

Quick installation test

Assuming your app has a recent template as used by the Cordova create script, add the following code to the onDeviceReady function, after app.receivedEvent('deviceready');:

  window.sqlitePlugin.openDatabase({ name: 'hello-world.db', location: 'default' }, function (db) {
    db.executeSql("select length('tenletters') as stringlength", [], function (res) {
      var stringlength = res.rows.item(0).stringlength;
      console.log('got stringlength: ' + stringlength);
      document.getElementById('deviceready').querySelector('.received').innerHTML = 'stringlength: ' + stringlength;
   });
  });

Support

Policy

Free support is provided on a best-effort basis and is only available in public forums. Please follow the steps below to be sure you have done your best before requesting help.

Commercial support is available by contacting: sales@litehelpers.net

Before asking for help

First steps:

and check the following:

  • You are using the latest version of the Plugin (Javascript and platform-specific part) from this repository.
  • The plugin is installed correctly.
  • You have included the correct version of cordova.js.
  • You have registered the plugin properly in config.xml.

If you still cannot get something to work:

If you continue to see the issue in the fresh, clean Cordova project:

  • Make the simplest test program you can to demonstrate the issue, including the following characteristics:
    • it completely self-contained, i.e. it is using no extra libraries beyond cordova & SQLitePlugin.js;
    • if the issue is with adding data to a table, that the test program includes the statements you used to open the database and create the table;
    • if the issue is with retrieving data from a table, that the test program includes the statements you used to open the database, create the table, and enter the data you are trying to retrieve.

Then you can raise the new issue.

Professional support

Professional support is available by contacting: sales@litehelpers.net

For more information: http://litehelpers.net/

What will be supported for free

Please make a small, self-contained test program that can demonstrate your problem and post it. Please do not use any other plugins or frameworks than are absolutely necessary to demonstrate your problem.

In case of a problem with a pre-populated database, please post your entire project.

Support for issues with Angular/"ngCordova"/Ionic

Free support for issues with Angular/"ngCordova"/Ionic will only be provided if you can demonstrate that you can do the same thing without such a framework.

  • Make a fresh, clean ngCordova or Ionic project with a test program that demonstrates the issue and post it. Please do not use any other plugins or frameworks unless absolutely necessary to demonstrate your issue.
  • Make another project without any form of Angular including ngCordova or Ionic, with the same test program to show that it will work outside Angular/"ngCordova"/Ionic.

What information is needed for help

Please include the following:

  • Which platform(s) (Android/iOS/macOS)
  • Clear description of the issue
  • A small, complete, self-contained program that demonstrates the problem, preferably as a Github project. ZIP/TGZ/BZ2 archive available from a public link is OK. No RAR or other such formats please!
  • A Cordova project is highly preferred. Intel, MS IDE, or similar project formats should be avoided.

Please do NOT use any of these formats

  • screen casts or videos
  • RAR or similar archive formats
  • Intel, MS IDE, or similar project formats unless absolutely necessary

Where to ask for help

Once you have followed the directions above, you may request free support in the following location(s):

Please include the information described above otherwise.

Professional support

Professional support is available, please contact: sales@litehelpers.net

Unit tests

Unit testing is done in spec.

running tests from shell

To run the tests from *nix shell, simply do either:

./bin/test.sh ios

or for Android:

./bin/test.sh android

To run from a windows powershell (here is a sample for android target):

.\bin\test.ps1 android

Adapters

WARNING: these adapters are not tested, not supported with web workers.

Lawnchair Adapter

PouchDB

Contributing

Community

NOTE: As stated above, patches will NOT be accepted on this project due to potential licensing issues. Issues with reproduction scenarios will help maintain and improve the quality of this plugin for future users.

Contact

sales@litehelpers.net