Add example for prepared query usage

7 files changed, 576 insertions, 0 deletions

diff --git a/README b/README
index 8b26963..bbaea80 100644
--- a/README
+++ b/README
@@ -47,6 +47,9 @@ inheritance/polymorphism
 view
   Shows how to define and use object, table, mixed, and native views.
 
+prepared
+  Shows how to use prepared queries.
+
 optimistic
   Shows how to use optimistic concurrency in ODB.
 
diff --git a/makefile b/makefile
index 31672fb..8f9c314 100644
--- a/makefile
+++ b/makefile
@@ -15,6 +15,7 @@ query                    \
 mapping                  \
 optimistic               \
 pimpl                    \
+prepared                 \
 schema/embedded
 
 tr1_dirs   := relationship inverse schema/custom view
diff --git a/prepared/README b/prepared/README
new file mode 100644
index 0000000..1fc6a0f
--- /dev/null
+++ b/prepared/README
@@ -0,0 +1,65 @@
+This example shows how to use prepared queries. In particular, it includes
+examples of cached and uncached queries, with and without by-reference
+parameters, as well as the use of a prepared query factory.
+
+The example consists of the following files:
+
+person.hxx
+  Header file defining the 'person' persistent class as well as the
+  'person_count' view.
+
+person-odb.hxx
+person-odb.ixx
+person-odb.cxx
+person.sql
+  The first three files contain the database support code and the last file
+  contains the database schema for the person.hxx header.
+
+  These files are generated by the ODB compiler from person.hxx using the
+  following command line:
+
+  odb -d <database> --generate-query --generate-prepared \
+--generate-schema person.hxx
+
+  Where <database> stands for the database system we are using, for example,
+  'mysql'.
+
+  The --generate-prepared option requests the generation of the prepared
+  query support code.
+
+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 person.hxx and person-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 and creates a number of persistent objects. It then prepares and
+  executes a number of queries to illustrate various usage scenarios.
+
+To compile and link the example manually from the command line we can use
+the following commands (using  MySQL as an example; replace 'c++' with your
+C++ compiler name):
+
+c++ -c person-odb.cxx
+c++ -DDATABASE_MYSQL -c driver.cxx
+c++ -o driver driver.o person-odb.o -lodb-mysql -lodb
+
+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 MySQL as an example, this
+can be achieved with the following command:
+
+mysql --user=odb_test --database=odb_test < person.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
diff --git a/prepared/database.hxx b/prepared/database.hxx
new file mode 100644
index 0000000..2e9316a
--- /dev/null
+++ b/prepared/database.hxx
@@ -0,0 +1,94 @@
+// file      : prepared/database.hxx
+// 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>
+#elif defined(DATABASE_SQLITE)
+#  include <odb/connection.hxx>
+#  include <odb/transaction.hxx>
+#  include <odb/schema-catalog.hxx>
+#  include <odb/sqlite/database.hxx>
+#elif defined(DATABASE_PGSQL)
+#  include <odb/pgsql/database.hxx>
+#elif defined(DATABASE_ORACLE)
+#  include <odb/oracle/database.hxx>
+#elif defined(DATABASE_MSSQL)
+#  include <odb/mssql/database.hxx>
+#else
+#  error unknown database; did you forget to define the DATABASE_* macros?
+#endif
+
+inline std::auto_ptr<odb::database>
+create_database (int& argc, char* argv[])
+{
+  using namespace std;
+  using namespace odb::core;
+
+  if (argc > 1 && argv[1] == string ("--help"))
+  {
+    cout << "Usage: " << argv[0] << " [options]" << endl
+         << "Options:" << endl;
+
+#if defined(DATABASE_MYSQL)
+    odb::mysql::database::print_usage (cout);
+#elif defined(DATABASE_SQLITE)
+    odb::sqlite::database::print_usage (cout);
+#elif defined(DATABASE_PGSQL)
+    odb::pgsql::database::print_usage (cout);
+#elif defined(DATABASE_ORACLE)
+    odb::oracle::database::print_usage (cout);
+#elif defined(DATABASE_MSSQL)
+    odb::mssql::database::print_usage (cout);
+#endif
+
+    exit (0);
+  }
+
+#if defined(DATABASE_MYSQL)
+  auto_ptr<database> db (new odb::mysql::database (argc, argv));
+#elif defined(DATABASE_SQLITE)
+  auto_ptr<database> db (
+    new odb::sqlite::database (
+      argc, argv, false, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE));
+
+  // Create the database schema. Due to bugs in SQLite foreign key
+  // support for DDL statements, we need to temporarily disable
+  // foreign keys.
+  //
+  {
+    connection_ptr c (db->connection ());
+
+    c->execute ("PRAGMA foreign_keys=OFF");
+
+    transaction t (c->begin ());
+    schema_catalog::create_schema (*db);
+    t.commit ();
+
+    c->execute ("PRAGMA foreign_keys=ON");
+  }
+#elif defined(DATABASE_PGSQL)
+  auto_ptr<database> db (new odb::pgsql::database (argc, argv));
+#elif defined(DATABASE_ORACLE)
+  auto_ptr<database> db (new odb::oracle::database (argc, argv));
+#elif defined(DATABASE_MSSQL)
+  auto_ptr<database> db (new odb::mssql::database (argc, argv));
+#endif
+
+  return db;
+}
+
+#endif // DATABASE_HXX
diff --git a/prepared/driver.cxx b/prepared/driver.cxx
new file mode 100644
index 0000000..470d0b8
--- /dev/null
+++ b/prepared/driver.cxx
@@ -0,0 +1,232 @@
+// file      : prepared/driver.cxx
+// copyright : not copyrighted - public domain
+
+#include <memory>   // std::auto_ptr
+#include <cassert>
+#include <iostream>
+
+#include <odb/database.hxx>
+#include <odb/connection.hxx>
+#include <odb/transaction.hxx>
+
+#include "database.hxx" // create_database
+
+#include "person.hxx"
+#include "person-odb.hxx"
+
+using namespace std;
+using namespace odb::core;
+
+struct params
+{
+  unsigned short age;
+  string first;
+};
+
+static void
+query_factory (const char* name, connection& c)
+{
+  typedef odb::query<person> query;
+
+  auto_ptr<params> p (new params);
+  query q (query::age > query::_ref (p->age) &&
+           query::first == query::_ref (p->first));
+  prepared_query<person> pq (c.prepare_query<person> (name, q));
+  c.cache_query (pq, p);
+}
+
+static void
+print_ages (unsigned short age, odb::result<person> r)
+{
+  cout << "over " << age << ':';
+
+  for (odb::result<person>::iterator i (r.begin ()); i != r.end (); ++i)
+    cout << ' ' << i->age ();
+
+  cout << endl;
+}
+
+int
+main (int argc, char* argv[])
+{
+  try
+  {
+    auto_ptr<database> db (create_database (argc, argv));
+
+    // Create a few persistent person objects.
+    //
+    {
+      person p1 ("John", "First",  91);
+      person p2 ("John", "Second", 81);
+      person p3 ("John", "Third",  71);
+      person p4 ("John", "Fourth", 61);
+      person p5 ("John", "Fifth",  51);
+
+      transaction t (db->begin ());
+      db->persist (p1);
+      db->persist (p2);
+      db->persist (p3);
+      db->persist (p4);
+      db->persist (p5);
+      t.commit ();
+    }
+
+    typedef odb::query<person> query;
+    typedef odb::prepared_query<person> prep_query;
+    typedef odb::result<person> result;
+
+    // Example of an uncached prepared query in the same transaction.
+    //
+    {
+      transaction t (db->begin ());
+
+      unsigned short age;
+      query q (query::age > query::_ref (age));
+      prep_query pq (db->prepare_query<person> ("person-age-query", q));
+
+      for (age = 90; age > 40; age -= 10)
+      {
+        result r (pq.execute ());
+        print_ages (age, r);
+      }
+
+      t.commit ();
+    }
+
+    // Example of an uncached prepared query in multiple transactions.
+    //
+    // Note that here we have to first obtain a connection, then prepare
+    // the query using this connection, and finally start each transaction
+    // that uses the prepared query on this connection.
+    //
+    {
+      connection_ptr conn (db->connection ());
+
+      unsigned short age;
+      query q (query::age > query::_ref (age));
+      prep_query pq (conn->prepare_query<person> ("person-age-query", q));
+
+      for (age = 90; age > 40; age -= 10)
+      {
+        transaction t (conn->begin ());
+
+        result r (pq.execute ());
+        print_ages (age, r);
+
+        t.commit ();
+      }
+    }
+
+    // Example of a cached prepared query without by-reference parameters.
+    //
+    for (unsigned short i (0); i < 5; ++i)
+    {
+      transaction t (db->begin ());
+
+      prep_query pq (db->lookup_query<person> ("person-val-age-query"));
+
+      if (!pq)
+      {
+        pq = db->prepare_query<person> (
+          "person-val-age-query", query::age > 50);
+        db->cache_query (pq);
+      }
+
+      result r (pq.execute ());
+      print_ages (50, r);
+
+      t.commit ();
+    }
+
+    // Example of a cached prepared query with by-reference parameters.
+    //
+    for (unsigned short age (90); age > 40; age -= 10)
+    {
+      transaction t (db->begin ());
+
+      unsigned short* age_param;
+      prep_query pq (
+        db->lookup_query<person> ("person-ref-age-query", age_param));
+
+      if (!pq)
+      {
+        auto_ptr<unsigned short> p (new unsigned short);
+        age_param = p.get ();
+        query q (query::age > query::_ref (*age_param));
+        pq = db->prepare_query<person> ("person-ref-age-query", q);
+        db->cache_query (pq, p); // Assumes ownership of p.
+      }
+
+      *age_param = age; // Initialize the parameter.
+      result r (pq.execute ());
+      print_ages (age, r);
+
+      t.commit ();
+    }
+
+    // Example of a cached prepared query that uses a query factory.
+    //
+    db->query_factory ("person-age-name-query", &query_factory);
+
+    for (unsigned short age (90); age > 40; age -= 10)
+    {
+      transaction t (db->begin ());
+
+      params* p;
+      prep_query pq (db->lookup_query<person> ("person-age-name-query", p));
+      assert (pq);
+
+      p->age = age;
+      p->first = "John";
+      result r (pq.execute ());
+      print_ages (age, r);
+
+      t.commit ();
+    }
+
+    // In C++11 the above call to query_factory() can be re-written to
+    // use a lambda function, for example:
+    //
+    /*
+    db->query_factory (
+      "person-age-name-query",
+      [] (const char* name, connection& c)
+      {
+        auto_ptr<params> p (new params);
+        query q (query::age > query::_ref (p->age) &&
+                 query::first == query::_ref (p->first));
+        prepared_query<person> pq (c.prepare_query<person> (name, q));
+        c.cache_query (pq, p);
+      });
+    */
+
+    // Prepared queries can also be used with views, as shown in the
+    // following example.
+    //
+    {
+      typedef odb::query<person_count> query;
+      typedef odb::prepared_query<person_count> prep_query;
+      typedef odb::result<person_count> result;
+
+      transaction t (db->begin ());
+
+      unsigned short age;
+      query q (query::age > query::_ref (age));
+      prep_query pq (
+        db->prepare_query<person_count> ("person-count-age-query", q));
+
+      for (age = 90; age > 40; age -= 10)
+      {
+        result r (pq.execute ());
+        cout << "over " << age << ": " << r.begin ()->count << endl;
+      }
+
+      t.commit ();
+    }
+  }
+  catch (const odb::exception& e)
+  {
+    cerr << e.what () << endl;
+    return 1;
+  }
+}
diff --git a/prepared/makefile b/prepared/makefile
new file mode 100644
index 0000000..c013f81
--- /dev/null
+++ b/prepared/makefile
@@ -0,0 +1,120 @@
+# file      : prepared/makefile
+# copyright : Copyright (c) 2009-2012 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 := person.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) -I$(src_base) -D$(db_macro)
+$(cxx_obj) $(cxx_od): $(odb.l.cpp-options) $(odb_db.l.cpp-options)
+
+genf := $(addprefix $(odb_hdr:.hxx=-odb),.hxx .ixx .cxx) $(odb_hdr:.hxx=.sql)
+gen  := $(addprefix $(out_base)/,$(genf))
+
+$(gen): $(odb)
+$(gen): odb := $(odb)
+$(gen) $(dist): export odb_options += --database $(db_id) --generate-query \
+--generate-prepared --generate-schema
+$(gen): cpp_options := -I$(src_base)
+$(gen): $(odb.l.cpp-options)
+
+$(call include-dep,$(cxx_od),$(cxx_obj),$(gen))
+
+# Alias for default target.
+#
+$(out_base)/: $(driver)
+
+# Dist
+#
+name := $(subst /,-,$(subst $(src_root)/,,$(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)) $(call vc11projs,$(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))
+	$(call meta-vc11projs,../template/template,$(name))
+
+# Test.
+#
+$(test): header := $(odb_hdr)
+$(test): $(driver)
+	$(call schema)
+	$(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,$(bld_root)/meta/vc11proj.make)
+$(call include,$(bld_root)/meta/automake.make)
+
+$(call include,$(bld_root)/cxx/standard.make) # cxx_standard
+ifdef cxx_standard
+$(gen): odb_options += --std $(cxx_standard)
+$(call include,$(odb_rules))
+endif
+
+$(call include,$(bld_root)/cxx/cxx-d.make)
+$(call include,$(bld_root)/cxx/cxx-o.make)
+$(call include,$(bld_root)/cxx/o-e.make)
+
diff --git a/prepared/person.hxx b/prepared/person.hxx
new file mode 100644
index 0000000..dc8e6fe
--- /dev/null
+++ b/prepared/person.hxx
@@ -0,0 +1,61 @@
+// file      : prepared/person.hxx
+// copyright : not copyrighted - public domain
+
+#ifndef PERSON_HXX
+#define PERSON_HXX
+
+#include <string>
+#include <cstddef> // std::size_t
+
+#include <odb/core.hxx>
+
+#pragma db object
+class person
+{
+public:
+  person (const std::string& first,
+          const std::string& last,
+          unsigned short age)
+      : first_ (first), last_ (last), age_ (age)
+  {
+  }
+
+  const std::string&
+  first () const
+  {
+    return first_;
+  }
+
+  const std::string&
+  last () const
+  {
+    return last_;
+  }
+
+  unsigned short
+  age () const
+  {
+    return age_;
+  }
+
+private:
+  friend class odb::access;
+
+  person () {}
+
+  #pragma db id auto
+  unsigned long id_;
+
+  std::string first_;
+  std::string last_;
+  unsigned short age_;
+};
+
+#pragma db view object(person)
+struct person_count
+{
+  #pragma db column("count(" + person::id_ + ")")
+  std::size_t count;
+};
+
+#endif // PERSON_HXX