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sqlpp11/tests/core/usage/Union.cpp
2021-08-01 20:37:36 +02:00

75 lines
3.1 KiB
C++

/*
* 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;
}