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diff --git a/odb-examples/boost/README b/odb-examples/boost/README new file mode 100644 index 0000000..dabacfc --- /dev/null +++ b/odb-examples/boost/README @@ -0,0 +1,79 @@ +This example shows how to persist objects that use Boost smart pointers, +containers, and value types with the help of the Boost profile library +(libodb-boost). + +The example consists of the following files: + +employee.hxx + Header file defining the 'employee' and 'employer' persistent classes. + We use shared_ptr/weak_ptr smart pointers provided by Boost (as well + as their lazy versions provided by the Boost profile library) to + establish a bidirectional employee-employer relationship. We also use + the boost::gregorian::date type to store the employee's date of birth + and the boost::unordered_set container to keep track of the employee's + email addresses. The employee's object id is boost::uuids::uuid. Finally, + we use boost::optional for the optional middle name. If the middle name + is not present, it will be represented in the database as a NULL value. + +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 --std c++11 -d <database> --profile boost --generate-schema \ + --generate-query --generate-session employee.hxx + + Where <database> stands for the database system we are using, for example, + 'pgsql'. + + The --profile option is used to instruct the ODB compiler to load the Boost + profile. The --generate-session option is used to enable session support + for all the persistent classes in employee.hxx. + +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 creates a number of 'employee' and 'employer' objects and + persists them in the database. The next transaction loads all the employees + of a particular employer using the employee-employer relationship. Finally, + the driver performs a few database queries which use data members of the + various Boost value types in their criterion. + +To compile and link the example manually from the command line we can use the +following commands (using PostgreSQL as an example; replace 'c++' with your +C++ compiler name): + +c++ -c employee-odb.cxx +c++ -DDATABASE_PGSQL -c driver.cxx +c++ -o driver driver.o employee-odb.o -lodb-boost -lodb-pgsql -lodb + +Note that libodb-boost doesn't link any Boost libraries and it is the user's +responsibility to link the necessary ones. + +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 PostgreSQL as an example, this +can be achieved with the following command: + +psql --username=odb_test --dbname=odb_test -f 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 PostgreSQL as +the database): + +./driver --user odb_test --database odb_test |