From 17d96bd351d0db6760706f2620b25353f1883ddd Mon Sep 17 00:00:00 2001 From: Boris Kolpackov Date: Wed, 19 Jan 2011 12:04:47 +0200 Subject: Add schema example It shows how to map persistent classes to a custom database schema. --- schema/README | 56 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+) create mode 100644 schema/README (limited to 'schema/README') diff --git a/schema/README b/schema/README new file mode 100644 index 0000000..373169f --- /dev/null +++ b/schema/README @@ -0,0 +1,56 @@ +This example shows how to map persistent C++ classes to a custom database +schema. In particular, it shows how to map all the commonly-used constructs, +including containers, object relationships, and composite value types. + +The example uses the shared_ptr smart pointer 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' and 'employer' persistent classes + as well as the 'name' composite value type. ODB pragmas are used to + assign custom database tables to persistent classes as well as custom + database types and columns to data members. + +employee-odb.hxx +employee-odb.ixx +employee-odb.cxx + These files contain the database support code for the employee.hxx header + and are generated by the ODB compiler from employee.hxx using the following + command line: + + odb -d --generate-query --default-pointer std::tr1::shared_ptr \ + employee.hxx + + Where 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 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 programmatically creates the database schema by executing + a series of SQL statements. After that the driver creates a number of + 'employee' and 'employer' objects, sets the relationships between them, + and persists them in the database. Finally, the driver performs a database + query and prints the information about the returned objects. + +To run the driver, using MySQL as an example, we can execute the following +command: + +./driver --user odb_test --database odb_test + +Here we use 'odb_test' as the database login and also 'odb_test' as the +database name. -- cgit v1.1