sqlpp11/tests/core/usage/Union.cpp

/*
 * Copyright (c) 2013-2015, Roland Bock
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *  * Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 *  * Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "Sample.h"
#include "MockDb.h"
#include <sqlpp11/select.h>
#include <sqlpp11/alias_provider.h>
#include <iostream>

namespace greek
{
  SQLPP_ALIAS_PROVIDER(alpha)
  SQLPP_ALIAS_PROVIDER(beta)
}

int Union(int, char* [])
{
  MockDb db;
  MockDb::_serializer_context_t printer = {};

  const auto t = test::TabBar{};
  const auto f = test::TabFoo{};

  db(select(t.alpha).from(t).unconditionally().union_distinct(select(f.epsilon.as(t.alpha)).from(f).unconditionally()));
  db(select(t.alpha).from(t).unconditionally().union_all(select(f.epsilon.as(t.alpha)).from(f).unconditionally()));

  // t.alpha can be null, a given value cannot
  db(select(t.alpha).from(t).unconditionally().union_all(select(sqlpp::value(1).as(t.alpha))));
  db(select(t.alpha).from(t).unconditionally().union_all(select(sqlpp::value(1).as(greek::alpha))));

  // t.beta can be null, f.delta cannot
  static_assert(sqlpp::can_be_null_t<decltype(t.beta)>::value, "");
  static_assert(!sqlpp::can_be_null_t<decltype(f.delta)>::value, "");
  db(select(t.beta).from(t).unconditionally().union_all(select(f.delta.as(greek::beta)).from(f).unconditionally()));

  auto u = select(t.alpha)
               .from(t)
               .unconditionally()
               .union_all(select(f.epsilon.as(t.alpha)).from(f).unconditionally())
               .as(sqlpp::alias::u);

  db(select(all_of(u)).from(u).unconditionally().union_all(select(t.delta.as(t.alpha)).from(t).unconditionally()));
  db(select(u.alpha).from(u).unconditionally().union_all(select(t.delta.as(t.alpha)).from(t).unconditionally()));

  db(select(t.alpha)
         .from(t)
         .unconditionally()
         .union_all(select(t.alpha).from(t).unconditionally())
         .union_all(select(t.alpha).from(t).unconditionally()));

  return 0;
}