diff options
Diffstat (limited to 'view')
| -rw-r--r-- | view/README | 68 | ||||
| -rw-r--r-- | view/database.hxx | 81 | ||||
| -rw-r--r-- | view/driver.cxx | 308 | ||||
| -rw-r--r-- | view/employee.hxx | 287 | ||||
| -rw-r--r-- | view/makefile | 115 |
5 files changed, 859 insertions, 0 deletions
diff --git a/view/README b/view/README new file mode 100644 index 0000000..108d234 --- /dev/null +++ b/view/README @@ -0,0 +1,68 @@ +This example shows how to declare and use views in ODB. It includes views +that show how to load a subset of data member from objects and tables, +perform aggregate queries, and join multiple objects and tables using +object relationships and custom join conditions. + +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 'country', 'employer', and 'employee' persistent + classes. The example also uses a "legacy" 'employee_extra' table that is + not mapped to a persistent class. + + After the persistent classes, this header defines a number of views that + show how to obtain various information from the above object model. + +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 -d <database> --generate-schema --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 creates the legacy 'employee_extra' table and proceeds + to populate the database with a number of 'employee', 'employer', and + 'project' objects. Once this is done, the driver uses views defined in + employee.hxx to load and print various information about the object model. + +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 < 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 MySQL as +the database): + +./driver --user odb_test --database odb_test diff --git a/view/database.hxx b/view/database.hxx new file mode 100644 index 0000000..c68e3e1 --- /dev/null +++ b/view/database.hxx @@ -0,0 +1,81 @@ +// file : view/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> +#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> +#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")) + { + cerr << "Usage: " << argv[0] << " [options]" << endl + << "Options:" << endl; + +#if defined(DATABASE_MYSQL) + odb::mysql::database::print_usage (cerr); +#elif defined(DATABASE_SQLITE) + odb::sqlite::database::print_usage (cerr); +#elif defined(DATABASE_PGSQL) + odb::pgsql::database::print_usage (cerr); +#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)); +#endif + + return db; +} + +#endif // DATABASE_HXX diff --git a/view/driver.cxx b/view/driver.cxx new file mode 100644 index 0000000..ccd8d2d --- /dev/null +++ b/view/driver.cxx @@ -0,0 +1,308 @@ +// file : view/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::core; + +int +main (int argc, char* argv[]) +{ + try + { + auto_ptr<database> db (create_database (argc, argv)); + + // Create the legacy employee_extra table. + // + { + // First try to drop the table if it exists. + // + { + transaction t (db->begin ()); + try + { + db->execute ("DROP TABLE view_employee_extra"); + t.commit (); + } + catch (const odb::exception&) + { + } + } + + { + transaction t (db->begin ()); + + db->execute ( + "CREATE TABLE view_employee_extra (" + "employee_id INTEGER NOT NULL," + "vacation_days INTEGER NOT NULL," + "previous_employer_id INTEGER)"); + + t.commit (); + } + } + + // Create a few persistent objects. + // + { + shared_ptr<country> ca (new country ("CA", "Canada")); + shared_ptr<country> za (new country ("ZA", "South Africa")); + shared_ptr<country> us (new country ("US", "United States")); + shared_ptr<country> se (new country ("SE", "Sweden")); + + shared_ptr<employer> st (new employer (1, "Simple Tech Ltd")); + shared_ptr<employer> cs (new employer (2, "Complex Systems Inc")); + + shared_ptr<employee> e1 ( + new employee (1, "John", "Doe", 29, ca, ca, st)); + + shared_ptr<employee> e2 ( + new employee (2, "Jane", "Doe", 30, za, us, cs)); + + shared_ptr<employee> e3 ( + new employee (3, "Joe", "Dirt", 31, us, za, st)); + + shared_ptr<employee> e4 ( + new employee (4, "Johan", "Johansen", 32, se, se, cs)); + + transaction t (db->begin ()); + + db->persist (ca); + db->persist (za); + db->persist (us); + db->persist (se); + + db->persist (st); + db->persist (cs); + + db->persist (e1); + db->persist (e2); + db->persist (e3); + db->persist (e4); + + // Populate the legacy table. + // + db->execute ("INSERT INTO view_employee_extra (" + "employee_id, vacation_days, previous_employer_id)" + "VALUES (1, 5, 2)"); + + db->execute ("INSERT INTO view_employee_extra (" + "employee_id, vacation_days, previous_employer_id)" + "VALUES (2, 10, NULL)"); + + db->execute ("INSERT INTO view_employee_extra (" + "employee_id, vacation_days, previous_employer_id)" + "VALUES (3, 0, NULL)"); + + db->execute ("INSERT INTO view_employee_extra (" + "employee_id, vacation_days, previous_employer_id)" + "VALUES (4, 15, 1)"); + + t.commit (); + } + + // Load names of the employees that are under 31 using the employee_name + // view. + // + { + typedef odb::query<employee_name> query; + typedef odb::result<employee_name> result; + + transaction t (db->begin ()); + + result r (db->query<employee_name> (query::age < 31)); + + cout << "Employees under 31" << endl; + + for (result::iterator i (r.begin ()); i != r.end (); ++i) + cout << " " << i->first << " " << i->last << endl; + + cout << endl; + + t.commit (); + } + + // Count the number of employees which has the Doe last name using the + // employee_count view. + // + { + transaction t (db->begin ()); + + result<employee_count> r ( + db->query<employee_count> (query<employee_count>::last == "Doe")); + + // Results of this aggregate query contains only one element. + // + cout << r.begin ()->count << " employees with the Doe last name" << endl + << endl; + + t.commit (); + } + + // Load the employee-employer information for all the employess with the + // Doe last name using the employee_employer view. + // + { + typedef odb::query<employee_employer> query; + typedef odb::result<employee_employer> result; + + transaction t (db->begin ()); + + // Note that we need to add the object name after query::. + // + result r (db->query<employee_employer> (query::employee::last == "Doe")); + + cout << "Employees with the Doe last name" << endl; + + for (result::iterator i (r.begin ()); i != r.end (); ++i) + cout << " " << i->first << " " << i->last << " " + << i->employer_name << endl; + + cout << endl; + + t.commit (); + } + + // Calculate average ages of all employees for each employer. + // + { + typedef odb::query<employer_age> query; + typedef odb::result<employer_age> result; + + transaction t (db->begin ()); + + result r (db->query<employer_age> ()); + + // Some other interesting queries to try: + // + // This one restricts the calculation to a specific employer: + // + // result r (db->query<employer_age> ( + // query::employer::name == "Simple Tech Ltd")); + // + // And this one filters the employees based on certain criteria. + // + // result r (db->query<employer_age> ( + // query::employee::last == "Doe")); + // + + cout << "Man/max employee ages" << endl; + + for (result::iterator i (r.begin ()); i != r.end (); ++i) + cout << " " << i->employer_name << " " + << i->min_age << '/' << i->max_age << endl; + + cout << endl; + + t.commit (); + } + + // Load the country information employees different residence and + // nationality. + // + { + typedef odb::query<employee_country> query; + typedef odb::result<employee_country> result; + + transaction t (db->begin ()); + + // Note that we use the alias given in the object pragma after query::. + // + result r (db->query<employee_country> ( + query::res_country::name != query::nat_country::name)); + + cout << "Employees residing outside of country of nationality" << endl; + + for (result::iterator i (r.begin ()); i != r.end (); ++i) + cout << " " << i->first << " " << i->last << " " + << i->res_country_name << " " << i->nat_country_name << endl; + + cout << endl; + + t.commit (); + } + + // Get the list of employees that have accumulated vacation days. + // + { + typedef odb::result<employee_vacation> result; + + transaction t (db->begin ()); + + // With native views we have to use the native query syntax. + // + result r (db->query<employee_vacation> ("vacation_days != 0")); + + cout << "Employees with accumulated vacation days" << endl; + + for (result::iterator i (r.begin ()); i != r.end (); ++i) + cout << " " << i->id << " " << i->days << endl; + + cout << endl; + + t.commit (); + } + + // Get the list of employees that have accumulated vacation days, + // this time using the improved employee_vacation2 view. + // + { + typedef odb::result<employee_vacation2> result; + + transaction t (db->begin ()); + + result r (db->query<employee_vacation2> ("vacation_days != 0")); + + cout << "Employees with accumulated vacation days (take 2)" << endl; + + for (result::iterator i (r.begin ()); i != r.end (); ++i) + cout << " " << i->first << " " << i->last << " " << i->days << endl; + + cout << endl; + + t.commit (); + } + + // Show the previous employers using the employee_prev_employer view. + // + { + typedef odb::query<employee_prev_employer> query; + typedef odb::result<employee_prev_employer> result; + + transaction t (db->begin ()); + + result r (db->query<employee_prev_employer> ()); + + cout << "Previous employees" << endl; + + for (result::iterator i (r.begin ()); i != r.end (); ++i) + { + const nullable<string>& pe (i->prev_employer_name); + + cout << " " << i->first << " " << i->last << " " + << (pe.null () ? string ("N/A") : *pe) << endl; + } + + cout << endl; + + t.commit (); + } + } + catch (const odb::exception& e) + { + cerr << e.what () << endl; + return 1; + } +} diff --git a/view/employee.hxx b/view/employee.hxx new file mode 100644 index 0000000..4ff4f1b --- /dev/null +++ b/view/employee.hxx @@ -0,0 +1,287 @@ +// file : view/employee.hxx +// author : Boris Kolpackov <boris@codesynthesis.com> +// copyright : not copyrighted - public domain + +#ifndef EMPLOYEE_HXX +#define EMPLOYEE_HXX + +#include <string> +#include <cstddef> // std::size_t + +#include <odb/core.hxx> +#include <odb/nullable.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; + +#pragma db object +class country +{ +public: + country (const std::string& code, std::string const& name) + : code_ (code), name_ (name) + { + } + + const std::string& + name () const + { + return name_; + } + +private: + friend class odb::access; + + country () {} + + #pragma db id + std::string code_; // ISO 2-letter country code. + + std::string name_; +}; + +#pragma db object +class employer +{ +public: + employer (unsigned long id, const std::string& name) + : id_ (id), name_ (name) + { + } + + const std::string& + name () const + { + return name_; + } + +private: + friend class odb::access; + + employer () {} + + #pragma db id + unsigned long id_; + + std::string name_; +}; + +#pragma db object +class employee +{ +public: + employee (unsigned long id, + const std::string& first, + const std::string& last, + unsigned short age, + shared_ptr<country> res, + shared_ptr<country> nat, + shared_ptr<employer> e) + : id_ (id), first_ (first), last_ (last), age_ (age), + residence_ (res), + nationality_ (nat), + employed_by_ (e) + { + } + + // Name. + // + const std::string& + first () const + { + return first_; + } + + const std::string& + last () const + { + return last_; + } + + // Employer. + // + shared_ptr<employer> + employed_by () const + { + return employed_by_; + } + + // Residence and nationality. + // + shared_ptr<country> + residence () const + { + return residence_; + } + + shared_ptr<country> + nationality () const + { + return nationality_; + } + +private: + friend class odb::access; + + employee () {} + + #pragma db id + unsigned long id_; + + std::string first_; + std::string last_; + + unsigned short age_; + + shared_ptr<country> residence_; + shared_ptr<country> nationality_; + + shared_ptr<employer> employed_by_; +}; + +// We also have a "legacy" employee_extra table that is not mapped to any +// object. It has the following columns: +// +// CREATE TABLE employee_extra( +// employee_id INTEGER NOT NULL, +// vacation_days INTEGER NOT NULL, +// previous_employer_id INTEGER) +// + +// A simple view with a single associated object. It allows us to get +// the name of an employee without loading any of the other data, such +// as the country and employer objects. The first and last data members +// in the view are automatically assumed to correspond to the first_ and +// last_ members in the employee object. +// +#pragma db view object(employee) +struct employee_name +{ + std::string first; + std::string last; +}; + +// A simple aggregate view. It allows us to count the number of employees +// matching certain criteria. Here we use a column expression with a +// reference to the id_ data member in the employee object. +// +#pragma db view object(employee) +struct employee_count +{ + #pragma db column("count(" + employee::id_ + ")") + std::size_t count; +}; + +// A simple view with two associated object. It allows us to get the +// name of an employee and its employer without loading any other data. +// Because there is a relationship between the employee and employer +// objects (employee::employed_by_), the ODB compiler automatically +// used this relationship as a join condition. Also, similar to the +// employee_name view, the first and last data members are automatically +// assumed to correspond to the first_ and last_ members in the employee +// object. For the employer_name member we provide an explicit member +// reference. +// +#pragma db view object(employee) object(employer) +struct employee_employer +{ + std::string first; + std::string last; + + #pragma db column(employer::name_) + std::string employer_name; +}; + +// A more interesting aggregate view using GROUP BY. It allows us to +// calculate the min/max age of employees for each employer. Here we +// use the C++-integrated syntax for the query condition template with +// a placeholder (?). +// +#pragma db view object(employee) object(employer) \ + query ((?) + "GROUP BY" + employer::name_) +struct employer_age +{ + #pragma db column(employer::name_) + std::string employer_name; + + #pragma db column("min(" + employee::age_ + ")") + unsigned short min_age; + + #pragma db column("max(" + employee::age_ + ")") + unsigned short max_age; +}; + +// A more complex view with three associated objects, two of which are +// of the same type, which requires us to use aliases and disambiguate +// the relationships used to join each object. +// +#pragma db view object(employee) \ + object(country = res_country: employee::residence_) \ + object(country = nat_country: employee::nationality_) +struct employee_country +{ + std::string first; + std::string last; + + #pragma db column(res_country::name_) + std::string res_country_name; + + #pragma db column(nat_country::name_) + std::string nat_country_name; +}; + +// A native view. A native view provides a complete query and is normally +// based on an ad-hoc table. This view allows us to load the employee +// vacation information from the legacy employee_extra table. +// +#pragma db view query("SELECT employee_id, vacation_days " \ + "FROM view_employee_extra") +struct employee_vacation +{ + #pragma db type("INTEGER") + unsigned long id; + + #pragma db type("INTEGER") + unsigned short days; +}; + +// An improved version of the previous view that extracts the employee +// first and last names instead of the id. To get the names we need to +// add the employee object to this view and use a custom join condition +// to tie it up with our legacy table. +// +#pragma db view table("view_employee_extra") \ + object(employee: "view_employee_extra.employee_id = " + employee::id_) +struct employee_vacation2 +{ + std::string first; + std::string last; + + #pragma db column("view_employee_extra.vacation_days") type("INTEGER") + unsigned short days; +}; + +// An advanced view that joins two objects via a legacy table. It returns +// the previous employer information for each employee. +// +#pragma db view object(employee) \ + table("view_employee_extra" = "extra": \ + "extra.employee_id = " + employee::id_) \ + object(employer: "extra.previous_employer_id = " + employer::id_) +struct employee_prev_employer +{ + std::string first; + std::string last; + + // If previous_employer_id is NULL, then the name will be NULL as well. + // We use the odb::nullable wrapper to handle this. + // + #pragma db column(employer::name_) + odb::nullable<std::string> prev_employer_name; +}; + +#endif // EMPLOYEE_HXX diff --git a/view/makefile b/view/makefile new file mode 100644 index 0000000..d1aeeec --- /dev/null +++ b/view/makefile @@ -0,0 +1,115 @@ +# file : view/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) -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 $(db_id) --generate-query \ +--generate-schema --default-pointer std::tr1::shared_ptr \ +--table-prefix view_ +$(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)) +$(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): 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,$(bld_root)/meta/automake.make) + +$(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) + |