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authorBoris Kolpackov <boris@codesynthesis.com>2011-01-13 11:31:14 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2011-01-13 11:31:14 +0200
commitab51fa65f9e8cad4ef5a1db85029dfe6404e9a1f (patch)
tree36c78dd50d88e4797f2bbb886c41399006111fea /inverse/README
parent5511613df7dce6142a84111488aaa25ff792d66b (diff)
Add composite, relationship, and inverse examples
All add the TR1 <memory> test for the latter two examples.
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+This example shows how to declare and use bidirectional one-to-one, one-to-
+many, and many-to-many relationships between persistent objects. It also
+shows how to work with lazy pointers. All the relationships presented in
+this example declare one side as inverse in order to produce canonical
+database schema.
+
+The example uses the shared_ptr and weak_ptr smart pointers from TR1 and
+requires a C++ compiler with TR1 support or an external TR1 implementation,
+such as the one provided by Boost.
+
+The example consists of the following files:
+
+employee.hxx
+ Header file defining the 'employee', 'employer', 'position', and 'project'
+ persistent classes as well as the employer-employee (one-to-many),
+ employee-position (one-to-one), and employee-project (many-to-many)
+ bidirectional relationships between them.
+
+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 \
+ --default-pointer std::tr1::shared_ptr employee.hxx
+
+ Where <database> stands for the database system we are using, for example,
+ 'mysql'.
+
+ The --default-pointer option is used to make TR1 shared_ptr the default
+ object pointer.
+
+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 'employee' class and the database support
+ code for this class. 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 creates a number of 'employee', 'employer', 'position',
+ and 'project' objects, sets the relationships between them, and persists
+ them in the database. In the next few transactions the driver loads various
+ objects, then accesses and modifies the relationships between them. Finally,
+ the driver performs a database query which uses a data member from a related
+ object in its criterion.
+
+To run the example we first need to create the database schema. 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