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diff --git a/inheritance/reuse/README b/inheritance/reuse/README new file mode 100644 index 0000000..8cba573 --- /dev/null +++ b/inheritance/reuse/README @@ -0,0 +1,61 @@ +This example shows how to use reuse inheritance with ODB. This inheritance +style normally lacks virtual functions and a virtual destructor in the base +class. The application code is normally written in terms of the derived +classes instead of the base. + +The other commonly used inheritance style is polymorphism inheritance. Refer +to the inheritance/polymorphism example for more information on this style. + +The example consists of the following files: + +employee.hxx + Header file defining the 'person' and 'employee' abstract persistent + classes as well as the 'permanent_employee', 'temporary_employee', and + 'contractor' concrete persistent classes. + +employee-odb.hxx +employee-odb.ixx +employee-odb.cxx +employee.sql + The first three files contain the database support code and the last file + contains the database schema for the employee.hxx header. + + These files are generated by the ODB compiler from employee.hxx using the + following command line: + + odb -d <database> --generate-schema --generate-query employee.hxx + + Where <database> stands for the database system we are using, for example, + 'mysql'. + +database.hxx + Contains the create_database() function which instantiates the concrete + database class corresponding to the database system we are using. + +driver.cxx + Driver for the example. It includes the employee.hxx and employee-odb.hxx + headers to gain access to the persistent classes and their database support + code. It also includes database.hxx for the create_database() function + declaration. + + In main() the driver first calls create_database() to obtain the database + instance. It then persists a number of permanent and temporary employee + objects as well as a number of contractor objects. The next transaction + looks up a contractor based on the email address. Finally, the driver + performs a database query which uses a data member from the base class + in its criterion. + +To run the example we may first need to create the database schema (for some +database systems, such as SQLite, the schema is embedded into the generated +code which makes this step unnecessary). Using MySQL as an example, this +can be achieved with the following command: + +mysql --user=odb_test --database=odb_test < employee.sql + +Here we use 'odb_test' as the database login and also 'odb_test' as the +database name. + +Once the database schema is ready, we can run the example (using MySQL as +the database): + +./driver --user odb_test --database odb_test |