The Selector Sample

This sample creates a DB_BOOK table in your database, enters sample data in it and lets you select rows from this table with author's name.

Compiling

To compile the example:

• Launch EiffelStudio.
• Select Use existing Ace (control file) and click OK.
• Browse to Eiffel52\examples\store\select\.
• Choose the file that fits your platform and the DBMS you want to use:
  • Ace.odbc.windows.ace on Windows platforms for ODBC DBMS drivers
  • Ace.oracle.windows.ace on Window platforms for Oracle DBMS
  • Ace.oracle.unix.ace on Unix platforms for Oracle DBMS
• Choose the directory where the project will be compiled, by default the same directory containing the Ace file.
• Click OK.

Running

Before running this sample, one must do link a specific file to data.sql as follows:

With Oracle:

ln data.sql.oracle data.sql

With ODBC:

ln data.sql.odbc data.sql

Caution: the data.sql file must be available in the sample application current directory. If you run the sample from EiffelStudio, this directory should be the EIFGEN/W_CODE/ directory of your project.

This sample lets you interact with your database through a console.

First you have to enter the database connection information:

• For ODBC:

Database user authentication:
Data Source Name: handson
Name: smith
Password: mypass

Note: Name and Password are no required with ODBC. If you don't need Name and Password, you can simply hit Return when prompted.

• For Oracle:

Database user authentication:
Name: smith@HANDSON
Password: mypass

Note: you have to specify the Oracle User Name and Net Service Name with the syntax <user>@<service> where <user> stands for the User Name and <service> stands for the Net Service Name.

Then you can select rows from this table with author's name, for instance:

Author? ('exit' to terminate):Bertrand Meyer
Seeking for books whose author's name match: Bertrand Meyer

Author:Bertrand Meyer
Title:Eiffel The Libraries
Quantity:11
Price:20
double_value:435.60000610351562
First publication:07/01/1994 12:00:00.0 AM


Author:Bertrand Meyer
Title:Eiffel The Language
Quantity:9
Price:51
double_value:775.22998046875
First publication:07/01/1992 12:00:00.0 AM



Author? ('exit' to terminate):

Note: enter exit to quit the application.

Under the Hood

This sample showcases the use of the DB_SELECTION class to perform smart select queries, using:

• Database data and Eiffel objects Coupling.
• Variables Binding.

The whole sample code is contained in the root class:

• SELECTOR for Oracle.
• SELECTOR_ODBC for ODBC.