aboutsummaryrefslogtreecommitdiff
path: root/schema/custom/README
diff options
context:
space:
mode:
Diffstat (limited to 'schema/custom/README')
-rw-r--r--schema/custom/README56
1 files changed, 56 insertions, 0 deletions
diff --git a/schema/custom/README b/schema/custom/README
new file mode 100644
index 0000000..373169f
--- /dev/null
+++ b/schema/custom/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 <database> --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 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.