Install Packages

From Lazarus wiki
Revision as of 10:40, 29 March 2005 by Matthijs (talk | contribs) (First: the why)


Due to popular demand here is a first attempt to create a small "Install package HOW-TO".

After installation of Lazarus a lot of starters wonder where the components for Database manipulation are. You can see a datasource and some data aware components, but where are the compontents to connect to a database (server) and to retreive data from this server?

Well let's have a look if we can find some of this stuff.

Files installed with Lazarus

Under Linux Lazarus gets installed by default in /usr/share/lazarus, in Windows the installer gives you a choice where to install the files, as long as there are no spaces in its path. On my Windows PC Lazarus got installed in G:/Lazarus. Whatever the base path of your Lazarus installation is, there you will find some subdirectories. In this case the first (alphabetically) sub directory looks rather promising to our goal as it is called components.

As you can see there are a few subdirectories there, which remind us of databases. One sees an Interbase, a mysql, a sqlite and a sqldb directory. The first three contain database connection components and TDataset descendants for the respective databases. The last one, sqldb, is more generic, as it consists of TSQLQuery (a TDataset) and TSQLTransaction which are used for all types of databases and a T??Connection to make the connection to the database. In this article we will install the sqldb-package together with the connection for Interbase.

The real work

First: the why

Before we start installing a package I like to discuss the why of Lazarus not installing database connection components. Database connection components need the client libraries to be available on the PC where the components are used. Because of the fact that at the moment Lazarus does not support dynamic linking, all libraries have to be compiled into the IDE. As you cannot expect every developer to have all databases installed it is not possible to install the connection components by default.

Second: But Delphi ...?

Delphi also only installs the database components which are readily available on the computer (ADO components) and components which do not need any client libraries (BDE: Paradox, DBase) to be installed.

Third: Lets install some stuff

To install a package one goes to "Components -> Open Package File (.lpk)" In the following dialog you navigate to /usr/share/lazarus/components/sqldb or the corresponding directory under Windows and choose the sqldblaz.lpk file. If everything works out as planned you will see the Package Manager. The Package Manager is showing a treeview with the files in the package and the required packages. Nothing to worry about let's just press Compile and when the compilation is finished press Install. Next we get a warning about Lazarus only supporting static linked libraries and the question if you want to rebuild Lazarus. Just press Yes and sit back. Lazarus will be rebuilt, and depending on your configuration restarted.

If everything went well you'll see a new tab called SQLdb. This tab will contain two components a TSQLConnection and a TSQLQuery. What we need next is a Connection component. Once again go to Components -> Open Package File and navigate to /usr/share/lazarus/components/sqldb/interbase. Open the ibconnectionlaz.lpk file and again press Compile and Install and Yes. :)

Next time Lazarus is started the SQLdb tab also contains a component TIBConnection.

Anything else?

Well that is all there is to it. You're now set to make your first program connecting to an Interbase server. See this sources to download with a small example. If you have any questions, go to the lazarus forum or post it to the lazarus mailing list.