Add schema example

It shows how to map persistent classes to a custom database schema.

5 files changed, 488 insertions, 0 deletions

diff --git a/schema/README b/schema/README
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+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.
diff --git a/schema/database.hxx b/schema/database.hxx
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+++ b/schema/database.hxx
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+// file      : schema/database.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : not copyrighted - public domain
+
+//
+// Create concrete database instance based on the DATABASE_* macros.
+//
+
+#ifndef DATABASE_HXX
+#define DATABASE_HXX
+
+#include <string>
+#include <memory>   // std::auto_ptr
+#include <cstdlib>  // std::exit
+#include <iostream>
+
+#include <odb/database.hxx>
+
+#if defined(DATABASE_MYSQL)
+#  include <odb/mysql/database.hxx>
+#endif
+
+inline std::auto_ptr<odb::database>
+create_database (int& argc, char* argv[])
+{
+  using namespace std;
+  using namespace odb;
+
+  if (argc > 1 && argv[1] == string ("--help"))
+  {
+    cerr << "Usage: " << argv[0] << " [options]" << endl
+         << "Options:" << endl;
+
+#if defined(DATABASE_MYSQL)
+    mysql::database::print_usage (cerr);
+#endif
+
+    exit (0);
+  }
+
+#if defined(DATABASE_MYSQL)
+  return auto_ptr<database> (new mysql::database (argc, argv));
+#endif
+}
+
+#endif // DATABASE_HXX
diff --git a/schema/driver.cxx b/schema/driver.cxx
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+++ b/schema/driver.cxx
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+// file      : schema/driver.cxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : not copyrighted - public domain
+
+#include <memory>   // std::auto_ptr
+#include <iostream>
+
+#include <odb/database.hxx>
+#include <odb/session.hxx>
+#include <odb/transaction.hxx>
+
+#include "database.hxx" // create_database
+
+#include "employee.hxx"
+#include "employee-odb.hxx"
+
+using namespace std;
+using namespace odb;
+
+int
+main (int argc, char* argv[])
+{
+  try
+  {
+    auto_ptr<database> db (create_database (argc, argv));
+
+    // Create the database schema.
+    //
+    {
+      transaction t (db->begin ());
+
+      // Try to drop the tables if they exist and ignore the error
+      // if they don't.
+      //
+      try
+      {
+        db->execute ("DROP TABLE Employer");
+        db->execute ("DROP TABLE Employee");
+        db->execute ("DROP TABLE EmployeeDegree");
+      }
+      catch (const odb::exception&)
+      {
+      }
+
+      db->execute (
+        "CREATE TABLE Employer ("
+        "name VARCHAR (255) NOT NULL PRIMARY KEY)");
+
+      db->execute (
+        "CREATE TABLE Employee ("
+        "ssn INTEGER UNSIGNED NOT NULL PRIMARY KEY,"
+        "first_name VARCHAR (255) NOT NULL,"
+        "last_name VARCHAR (255) NOT NULL,"
+        "employer VARCHAR (255) NOT NULL REFERENCES Employer (name))");
+
+      db->execute (
+        "CREATE TABLE EmployeeDegree ("
+        "ssn INTEGER UNSIGNED NOT NULL REFERENCES Employee (ssn),"
+        "degree VARCHAR (255) NOT NULL)");
+
+      t.commit ();
+    }
+
+    // Create a few persistent objects.
+    //
+    {
+      shared_ptr<employer> st (new employer ("Simple Tech Ltd"));
+
+      shared_ptr<employee> john (new employee (1, "John", "Doe", st));
+      shared_ptr<employee> jane (new employee (2, "Jane", "Doe", st));
+
+      john->degrees ().push_back ("BA");
+      john->degrees ().push_back ("MSc");
+      jane->degrees ().push_back ("Ph.D.");
+
+      transaction t (db->begin ());
+
+      db->persist (st);
+      db->persist (john);
+      db->persist (jane);
+
+      t.commit ();
+    }
+
+    // Load employees with "Doe" as the last name and print what we've got.
+    //
+    {
+      typedef odb::query<employee> query;
+      typedef odb::result<employee> result;
+
+      session s;
+      transaction t (db->begin ());
+
+      result r (db->query<employee> (query::name::last == "Doe"));
+
+      for (result::iterator i (r.begin ()); i != r.end (); ++i)
+      {
+        cout << i->name ().first () << " " << i->name ().last () << endl
+             << "  employer: " << i->employer ()->name () << endl;
+
+        for (degrees::iterator j (i->degrees ().begin ());
+             j != i->degrees ().end ();
+             ++j)
+        {
+          cout << "  degree: " << *j << endl;
+        }
+
+        cout << endl;
+      }
+
+      t.commit ();
+    }
+  }
+  catch (const odb::exception& e)
+  {
+    cerr << e.what () << endl;
+    return 1;
+  }
+}
diff --git a/schema/employee.hxx b/schema/employee.hxx
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+++ b/schema/employee.hxx
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+// file      : schema/employee.hxx
+// author    : Boris Kolpackov <boris@codesynthesis.com>
+// copyright : not copyrighted - public domain
+
+#ifndef EMPLOYEE_HXX
+#define EMPLOYEE_HXX
+
+#include <vector>
+#include <string>
+
+#include <odb/core.hxx>
+
+// Include TR1 <memory> header in a compiler-specific fashion. Fall back
+// on the Boost implementation if the compiler does not support TR1.
+//
+#include <odb/tr1/memory.hxx>
+
+using std::tr1::shared_ptr;
+
+typedef std::vector<std::string> degrees;
+
+#pragma db value
+class name
+{
+public:
+  name (const std::string& first, const std::string& last)
+      : first_ (first), last_ (last)
+  {
+  }
+
+  const std::string&
+  first () const
+  {
+    return first_;
+  }
+
+  const std::string&
+  last () const
+  {
+    return last_;
+  }
+
+private:
+  friend class odb::access;
+
+  #pragma db type("VARCHAR(255) NOT NULL") column("first_name")
+  std::string first_;
+
+  #pragma db type("VARCHAR(255) NOT NULL") column("last_name")
+  std::string last_;
+};
+
+#pragma db object table("Employer")
+class employer
+{
+public:
+  employer (const std::string& name)
+      : name_ (name)
+  {
+  }
+
+  const std::string&
+  name () const
+  {
+    return name_;
+  }
+
+private:
+  friend class odb::access;
+
+  employer () {}
+
+  #pragma db id type("VARCHAR(255) NOT NULL") column("name")
+  std::string name_;
+};
+
+#pragma db object table("Employee")
+class employee
+{
+public:
+  typedef ::employer employer_type;
+
+  employee (unsigned long id,
+            const std::string& first,
+            const std::string& last,
+            shared_ptr<employer_type> employer)
+      : id_ (id), name_ (first, last), employer_ (employer)
+  {
+  }
+
+  // Name.
+  //
+  typedef ::name name_type;
+
+  const name_type&
+  name () const
+  {
+    return name_;
+  }
+
+  // Degrees.
+  //
+  typedef ::degrees degrees_type;
+
+  const degrees_type&
+  degrees () const
+  {
+    return degrees_;
+  }
+
+  degrees_type&
+  degrees ()
+  {
+    return degrees_;
+  }
+
+  // Employer.
+  //
+  shared_ptr<employer_type>
+  employer () const
+  {
+    return employer_;
+  }
+
+  void
+  employer (shared_ptr<employer_type> employer)
+  {
+    employer_ = employer;
+  }
+
+private:
+  friend class odb::access;
+
+  employee (): name_ ("", "") {}
+
+  #pragma db id type("INTEGER UNSIGNED NOT NULL") column("ssn")
+  unsigned long id_;
+
+  #pragma db column("") // No column prefix.
+  name_type name_;
+
+  #pragma db unordered table("EmployeeDegree") id_column("ssn") \
+    value_type("VARCHAR(255) NOT NULL") value_column("degree")
+  degrees_type degrees_;
+
+  #pragma db not_null column("employer")
+  shared_ptr<employer_type> employer_;
+};
+
+#endif // EMPLOYEE_HXX
diff --git a/schema/makefile b/schema/makefile
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+++ b/schema/makefile
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+# file      : schema/makefile
+# author    : Boris Kolpackov <boris@codesynthesis.com>
+# copyright : Copyright (c) 2009-2011 Code Synthesis Tools CC
+# license   : GNU GPL v2; see accompanying LICENSE file
+
+include $(dir $(lastword $(MAKEFILE_LIST)))../build/bootstrap.make
+
+cxx_tun := driver.cxx
+odb_hdr := employee.hxx
+cxx_obj := $(addprefix $(out_base)/,$(cxx_tun:.cxx=.o) $(odb_hdr:.hxx=-odb.o))
+cxx_od  := $(cxx_obj:.o=.o.d)
+
+driver  := $(out_base)/driver
+dist    := $(out_base)/.dist
+test    := $(out_base)/.test
+clean   := $(out_base)/.clean
+
+# Import.
+#
+$(call import,\
+  $(scf_root)/import/odb/stub.make,\
+  odb: odb,odb-rules: odb_rules)
+
+$(call import,\
+  $(scf_root)/import/libodb/stub.make,\
+  l: odb.l,cpp-options: odb.l.cpp-options)
+
+ifdef db_id
+$(call import,\
+  $(scf_root)/import/libodb-$(db_id)/stub.make,\
+  l: odb_db.l,cpp-options: odb_db.l.cpp-options)
+endif
+
+ifeq ($(odb_db.l.cpp-options),)
+odb_db.l.cpp-options := $(out_base)/.unbuildable
+endif
+
+# Build.
+#
+$(driver): $(cxx_obj) $(odb_db.l) $(odb.l)
+$(cxx_obj) $(cxx_od): cpp_options := -I$(out_base)
+$(cxx_obj) $(cxx_od): $(odb.l.cpp-options) $(odb_db.l.cpp-options)
+
+ifeq ($(db_id),mysql)
+$(cxx_obj) $(cxx_od): cpp_options += -DDATABASE_MYSQL
+endif
+
+genf := $(addprefix $(odb_hdr:.hxx=-odb),.hxx .ixx .cxx)
+gen  := $(addprefix $(out_base)/,$(genf))
+
+$(gen): $(odb)
+$(gen): odb := $(odb)
+$(gen) $(dist): export odb_options += --database $(db_id) --generate-query \
+--default-pointer std::tr1::shared_ptr
+$(gen): cpp_options := -I$(out_base)
+$(gen): $(odb.l.cpp-options)
+
+$(call include-dep,$(cxx_od),$(cxx_obj),$(gen))
+
+# Alias for default target.
+#
+$(out_base)/: $(driver)
+
+# Dist
+#
+name := $(notdir $(src_base))
+
+$(dist): db_id := @database@
+$(dist): sources := $(cxx_tun)
+$(dist): headers := $(odb_hdr)
+$(dist): export name := $(name)
+$(dist): export odb_header_stem := $(basename $(odb_hdr))
+$(dist): export extra_dist := README $(call vc9projs,$(name)) \
+$(call vc10projs,$(name))
+$(dist):
+	$(call dist-data,$(sources) $(headers) README database.hxx)
+	$(call meta-automake,../template/Makefile.am)
+	$(call meta-vc9projs,../template/template,$(name))
+	$(call meta-vc10projs,../template/template,$(name))
+
+# Test.
+#
+$(test): schema := $(src_base)/$(basename $(odb_hdr)).sql
+$(test): $(driver)
+	$(call message,test $<,$< --options-file $(dcf_root)/db.options)
+
+# Clean.
+#
+$(clean):                            \
+  $(driver).o.clean                  \
+  $(addsuffix .cxx.clean,$(cxx_obj)) \
+  $(addsuffix .cxx.clean,$(cxx_od))  \
+  $(addprefix $(out_base)/,$(odb_hdr:.hxx=-odb.cxx.hxx.clean))
+
+# Generated .gitignore.
+#
+ifeq ($(out_base),$(src_base))
+$(driver): | $(out_base)/.gitignore
+
+$(out_base)/.gitignore: files := driver $(genf)
+$(clean): $(out_base)/.gitignore.clean
+
+$(call include,$(bld_root)/git/gitignore.make)
+endif
+
+# How to.
+#
+$(call include,$(bld_root)/dist.make)
+$(call include,$(bld_root)/meta/vc9proj.make)
+$(call include,$(bld_root)/meta/vc10proj.make)
+$(call include,$(bld_root)/meta/automake.make)
+
+$(call include,$(odb_rules))
+$(call include,$(bld_root)/cxx/cxx-d.make)
+$(call include,$(bld_root)/cxx/cxx-o.make)
+$(call include,$(bld_root)/cxx/o-e.make)
+