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mirror of https://github.com/rbock/sqlpp11.git synced 2024-11-15 20:31:16 +08:00

Corrected inconsistency in select value_type

This commit is contained in:
rbock 2014-02-08 23:48:35 +01:00
parent 88fc0959b5
commit 61ed1d9f37
3 changed files with 9 additions and 8 deletions

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@ -69,6 +69,12 @@ namespace sqlpp
{ {
using _column_list_t = ColumnList; using _column_list_t = ColumnList;
using _from_t = ColumnList; using _from_t = ColumnList;
using _value_type = typename std::conditional<
sqlpp::is_from_t<From>::value,
typename ColumnList::_value_type,
no_value_t // If there is no from, the select is not complete (this logic is a bit simple, but better than nothing)
>::type;
template<typename Database> template<typename Database>
struct can_run_t struct can_run_t
{ {
@ -87,7 +93,7 @@ namespace sqlpp
// SELECT // SELECT
template<typename Database, typename... Policies> template<typename Database, typename... Policies>
struct select_t: public vendor::policy_t<Policies>..., public vendor::crtp_wrapper_t<select_t<Database, Policies...>, Policies>..., struct select_t: public vendor::policy_t<Policies>..., public vendor::crtp_wrapper_t<select_t<Database, Policies...>, Policies>...,
public detail::select_helper_t<Policies...>::_column_list_t::_value_type::template operators<select_t<Database, Policies...>> public detail::select_helper_t<Policies...>::_value_type::template operators<select_t<Database, Policies...>>
{ {
template<typename Needle, typename Replacement> template<typename Needle, typename Replacement>
using _policy_update_t = select_t<Database, vendor::policy_update_t<Policies, Needle, Replacement>...>; using _policy_update_t = select_t<Database, vendor::policy_update_t<Policies, Needle, Replacement>...>;
@ -103,8 +109,7 @@ namespace sqlpp
using _is_select = std::true_type; using _is_select = std::true_type;
using _requires_braces = std::true_type; using _requires_braces = std::true_type;
// FIXME: introduce checks whether this select could really be used as a value using _value_type = typename detail::select_helper_t<Policies...>::_value_type;
using _value_type = typename _column_list_t::_value_type;
using _name_t = typename _column_list_t::_name_t; using _name_t = typename _column_list_t::_name_t;
select_t() select_t()

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@ -79,7 +79,6 @@ namespace sqlpp
struct no_from_t struct no_from_t
{ {
using _is_from = std::true_type;
const no_from_t& _from() const { return *this; } const no_from_t& _from() const { return *this; }
}; };

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@ -159,8 +159,6 @@ int main()
// Test a select of a single column without a from // Test a select of a single column without a from
{ {
using T = decltype(select(t.alpha)); // Hint: The current rule is pretty crude (a from is required), but certainly better than nothing using T = decltype(select(t.alpha)); // Hint: The current rule is pretty crude (a from is required), but certainly better than nothing
#warning Need to reactivate these tests
/*
static_assert(not sqlpp::is_numeric_t<T>::value, "type requirement"); static_assert(not sqlpp::is_numeric_t<T>::value, "type requirement");
static_assert(not sqlpp::is_expression_t<T>::value, "type requirement"); static_assert(not sqlpp::is_expression_t<T>::value, "type requirement");
static_assert(not sqlpp::is_named_expression_t<T>::value, "type requirement"); static_assert(not sqlpp::is_named_expression_t<T>::value, "type requirement");
@ -172,7 +170,6 @@ int main()
static_assert(not sqlpp::is_alias_t<T>::value, "type requirement"); static_assert(not sqlpp::is_alias_t<T>::value, "type requirement");
static_assert(not sqlpp::is_table_t<T>::value, "type requirement"); static_assert(not sqlpp::is_table_t<T>::value, "type requirement");
static_assert(sqlpp::is_regular<T>::value, "type requirement"); static_assert(sqlpp::is_regular<T>::value, "type requirement");
*/
} }
// Test a select of a single numeric table column // Test a select of a single numeric table column
@ -360,7 +357,7 @@ int main()
static_assert(sqlpp::is_named_expression_t<decltype(t.alpha)>::value, "alpha should be a named expression"); static_assert(sqlpp::is_named_expression_t<decltype(t.alpha)>::value, "alpha should be a named expression");
static_assert(sqlpp::is_named_expression_t<decltype(t.alpha.as(alias::a))>::value, "an alias of alpha should be a named expression"); static_assert(sqlpp::is_named_expression_t<decltype(t.alpha.as(alias::a))>::value, "an alias of alpha should be a named expression");
static_assert(sqlpp::is_alias_t<decltype(t.alpha.as(alias::a))>::value, "an alias of alpha should be an alias"); static_assert(sqlpp::is_alias_t<decltype(t.alpha.as(alias::a))>::value, "an alias of alpha should be an alias");
auto z = select(t.alpha) == 7; auto z = select(t.alpha).from(t) == 7;
auto l = t.as(alias::left); auto l = t.as(alias::left);
auto r = select(t.gamma.as(alias::a)).from(t).where(t.gamma == true).as(alias::right); auto r = select(t.gamma.as(alias::a)).from(t).where(t.gamma == true).as(alias::right);
static_assert(sqlpp::is_boolean_t<decltype(select(t.gamma).from(t))>::value, "select(bool) has to be a bool"); static_assert(sqlpp::is_boolean_t<decltype(select(t.gamma).from(t))>::value, "select(bool) has to be a bool");