AGB  ·  Datenschutz  ·  Impressum  







Anmelden
Nützliche Links
Registrieren

Delphi - SQLite Sample Projects

Ein Thema von DP News-Robot · begonnen am 22. Mär 2020
Antwort Antwort
Benutzerbild von DP News-Robot
DP News-Robot

Registriert seit: 4. Jun 2010
11.547 Beiträge
 
#1

Delphi - SQLite Sample Projects

  Alt 22. Mär 2020, 04:22
I've been exploring SQLite within Delphi. There are several sample SQLite applications that come with Delphi if you selected to install the samples during setup. I've put together the list of SQLite samples that are available.

The common samples file path is located here:
..\Studio\20.0\Samples\Object Pascal\Database\FireDAC\Samples\
FireDAC.SQLiteIniFile Demo Sample

This sample uses FireDAC to connect to an SQLite database that emulates the structure and the operations of an INI File.

AddOn\SQLiteIniFile\Demo\SQLiteIniDemo.dproj
FireDAC.TFDLocalSQL MegaFMX Sample

The sample shows different TFDLocalSQL applications.

Comp Layer\TFDLocalSQL\MegaFMX\LSQLMega.dprojFireDAC.SQLite Encryption Sample

This sample demonstrates how to encrypt/decrypt an SQLite database.

DBMS Specific\SQLite\Encryption\SQLite_Encrypt.dprojControlling Database Access Rights

The SQLite is an embedded DBMS. This implies that it is a single user DBMS and does not need such concepts as a user, access rights, and so on. Still, some application can benefit from an access right control, for example:
  • An application can restrict rights depending on an end-user license. A demo license means less possibilities, a full license provides all possibilities.
  • Multi-tier data access frameworks can use their own user concept and control data access rights using some generic approach.
Again, SQLite provides a unique feature allowing you to authorize or not SQL commands. To work with this API, a Delphi application should set the OnAutorize event handler of the TSQLiteDatabase object, which is a database connection wrapping object. Hook this event after a database connection is opened.

DBMS Specific\SQLite\OnAuthorize\SQLite_OnAuthorize.dpr ojHooking Database Updates

SQLite provides an unique API allowing you to monitor all updates to a database. This feature can be used, for example, to log all updates to a DB. To work with this API, a Delphi application should set the OnUpdate event handler of the TSQLiteDatabase object, which is a database connection wrapping object. Hook this event after a database connection is opened.

DBMS Specific\SQLite\OnUpdate\SQLite_OnUpdate.dprojCustom Collations

SQLite stores and handles all character data either in UTF8 or UTF16, depending on the OpenMode connection parameter. When SQLite needs to compare or sort a character data, it has to know what rules to use for this. The rules are known as a collation.

DBMS Specific\SQLite\UserCollation\SQLite_UserColl.dpro jCustom Functions

SQLite does not support the stored procedure or function concept, as it allows you to use the host language environment to extend the engine functionality. SQLite allows you to register host language functions in the SQLite engine and use them in the SQL commands. FireDAC simplifies this by introducing the TFDSQLiteFunction component.

DBMS Specific\SQLite\UserFunc\SQLite_UserFunc.dprojThe SQLite R*Tree Module

An R-Tree is a special index that is designed for doing range queries. R-Trees are most commonly used in geospatial systems where each entry is a rectangle with minimum and maximum X and Y coordinates. Given a query rectangle, an R-Tree is able to quickly find all entries that are contained within the query rectangle or which overlap the query rectangle.

This idea is easily extended to three dimensions for use in CAD systems. R-Trees also find use in time-domain range look-ups. For example, suppose a database records the starting and ending times for a large number of events. A R-Tree is able to quickly find all events that were active at any time during a given time interval, or all events that started during a particular time interval, or all events that both started and ended within a given time interval. And so forth.

DBMS Specific\SQLite\UserRTree\SQLite_UserRTree.dproj
Title: SQLite

Brief Description: This snippet shows you how to populate a listbox from a SQLite database using FireDAC and LiveBindings. See the section called "Accessing a Database" in the Mobile Tuturials topic in the documentation for more information and licensing requirements.

Platforms supported: iOS, Android

..\Mobile Snippets\FireDACSQLite\FireDAC_SQLite.dproj
Enjoy
Semper Fi,
Gunny Mike




Weiterlesen...
  Mit Zitat antworten Zitat
Themen-Optionen Thema durchsuchen
Thema durchsuchen:

Erweiterte Suche
Ansicht

Forumregeln

Es ist dir nicht erlaubt, neue Themen zu verfassen.
Es ist dir nicht erlaubt, auf Beiträge zu antworten.
Es ist dir nicht erlaubt, Anhänge hochzuladen.
Es ist dir nicht erlaubt, deine Beiträge zu bearbeiten.

BB-Code ist an.
Smileys sind an.
[IMG] Code ist an.
HTML-Code ist aus.
Trackbacks are an
Pingbacks are an
Refbacks are aus

Gehe zu:

Impressum · AGB · Datenschutz · Nach oben
Alle Zeitangaben in WEZ +1. Es ist jetzt 21:02 Uhr.
Powered by vBulletin® Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
LinkBacks Enabled by vBSEO © 2011, Crawlability, Inc.
Delphi-PRAXiS (c) 2002 - 2019 by Daniel R. Wolf