Elipse Knowledgebase

• information access control.
• optimized queries.
• data security.
• support to the network.
• support to procedures.
• storage capacity.
• support transactions.

Each one of these characteristics was commented on, and the analysis of all advantages raised by that article made it clear that this is the ideal solution for the majority of automation and supervision systems generating data that needs to be stored and checked frequently.

A serious hindrance for the propagation of database server systems is their costs. Among them, we have:

• Software licenses: although many companies distributing these servers offer packs suited for each client's profile, the initial license cost is too high when compared to the license cost of MS Access, E3's default file format, for example.
• Employees training: not every company has in their staff employees trained for maintenance and management tasks with these servers.
• Investment in server: depending on the selected database, there needs to be a high investment in dedicated server machines using a differentiated hardware, such as redundant disks and SCSI interfaces usually running under operational systems, such as Unix's several versions, among others.

Among the many database tools available in the market is the previously discussed Microsoft SQL Server, known as the simplest tool to be used and managed. To solve this cost problem on your project it is possible to use MSDE, a free version of Microsoft's software. MSDE has limited database size and limited amount of tools, but meets most part of supervisory projects needs.


2) Software and tools: installation and configuration

The software MSDE is available at E3's installation CD, and can also be downloaded from Microsoft's site. Its basic configuration has no database setting tools, just some basic programs, most of them with DOS interface.

After the software has been installed, the first step is to configure the database so that E3 can access it. To do so, there are at least three possibilities: using the tool SQL Enterprise Manager (enclosed in MS SQL Server complete installation); using Web Data Administrator; or using the software OSQL (enclosed in MSDE basic installation).


SQL Enterprise Manager

This is the software used by MS SQL Server to manage databases. It allows creating or altering users accounts, configuring users authentication mode, including new databases, etc. This software has been analyzed and explained at the documentation regarding MS SQL Server used with E3 at Elipse's homepage, in the section Articles. Its installation comes along with the software MS SQL Server, and the option to install this software's client software should be enough to install Enterprise Manager.

For further information regarding this software’s usage and installation, see the documentation previously referred.


Web Data Administrator

Web Data Administrator is a tool which allows configuring MSDE via a very simple Internet interface. There are restrictions regarding the use of this tool because the software must be downloaded from the Internet (at http://www.microsoft.com/downloads/ thankyou.aspx?FamilyID=c039a798-c57a-419e-acbc-2a332cb7f959&displaylang=en), and it is necessary that it operates conjoined with Microsoft .Net Framework 1.1 (which must also be downloaded from the site Microsoft Windows Update). Besides, IIS (Windows Internet server) must be installed in the machine where E3 will run, which is not always the case.


OSQL

The software OSQL is a program that runs via command line. Before using it, it is necessary to perform some configurations at Windows Registry.

To configure MSDE via software OSQL it is necessary, first of all, that the software MSDE is installed. Next, you must alter the way the database authenticates users at Windows Registry.

To do so, run the command regedit on the command line at Windows Start menu. Then, look for the key LoginMode, at HKEY_LOCALMACHINE\SOFTWARE\Microsoft \MSSQLServer\MSSQLServer. Alter its value to "2" (which corresponds to authentication via SQL Server) and then go to the key DefaultLogin to alter its value to "sa". MSDE considers DefaultLogin as default user login, and does not add any password to this login. Any additional security measure for the database being installed can be implemented by using Enterprise Manager or OSQL (as seen in this article) via SQL commands.

Soon after authentication mode and default login are configured, start a command line session (type "cmd" on Windows Start menu, at Run). Next, go to the folder where MSDE is installed. To do so, execute the commands listed below:

• Go to Start menu and select the option Run.
• Type the command cmd.
• A command window is then open. On this window, go to MSDE's Bin folder. To do so, run the command cd\, and next type the command:
   cd arquivos de programas\microsoft SQL Server\80\Tools\Bin
  
• After that, run the command:
   OSQL –U as –q "Create database E3Database"
  
• A password is asked to log in; then, press [Enter] (to keep the password field blank).
• Finally, a message is displayed informing that the database has been created. A second log file is also created, and its message displayed.
• To leave OSQL, press [Ctrl]+C.

From this point on, the Database is ready to be used by E3, according to the necessary configurations to access an SQL Server database. The parameters necessary to access the newly created database, as well as a small list of possible errors and their respective solutions, can be seen in the previously mentioned document on SQL Server database usage at E3.


3) Conclusion

The choice of a database depends on technical criteria, and can be restricted due to the cost of implementing the project. With MSDE, Microsoft's free software discussed in this article, you can eliminate the problems of database installation cost.

Notice that the limitation on management tools, as well as the database's total capacity, can make the use of this software to substitute the complete, unrestricted software MS SQL Server prohibitive. However, as an alternative with no cost to Access, this system is highly recommended.