Represents a one-to-one relationship. More...

#include <BelongsTo.hpp>

Public Types
using	ReferencedRecord = MemberClassType< decltype(TheReferencedField)>
	Represents the record type of the other field.

using	ValueType = typename std::remove_cvref_t< decltype(std::declval< ReferencedRecord >().*ReferencedField)>::ValueType
	Represents the column type of the foreign key, matching the primary key of the other record.

Public Member Functions
template<typename... S> requires std::constructible_from<ValueType, S...>
constexpr	BelongsTo (S &&... value) noexcept

constexpr	BelongsTo (ReferencedRecord const &other) noexcept

constexpr	BelongsTo (SelfType const &other) noexcept

constexpr	BelongsTo (SelfType &&other) noexcept

BelongsTo &	operator= (SqlNullType) noexcept

BelongsTo &	operator= (ReferencedRecord &other)

BelongsTo &	operator= (SelfType const &other)

LIGHTWEIGHT_FORCE_INLINE constexpr void	SetModified (bool value) noexcept
	Marks the field as modified or unmodified.

LIGHTWEIGHT_FORCE_INLINE constexpr bool	IsModified () const noexcept
	Checks if the field is modified.

LIGHTWEIGHT_FORCE_INLINE constexpr ValueType const &	Value () const noexcept
	Retrieves the reference to the value of the field.

LIGHTWEIGHT_FORCE_INLINE constexpr ValueType &	MutableValue () noexcept
	Retrieves the mutable reference to the value of the field.

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord &	Record ()
	Retrieves a record from the relationship.

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord const &	Record () const
	Retrieves an immutable reference to the record from the relationship.

LIGHTWEIGHT_FORCE_INLINE constexpr bool	IsLoaded () const noexcept
	Checks if the record is loaded into memory.

LIGHTWEIGHT_FORCE_INLINE void	Unload () noexcept
	Unloads the record from memory.

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord &	operator* () noexcept
	Retrieves the record from the relationship.

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord const &	operator* () const noexcept
	Retrieves the record from the relationship.

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord *	operator-> ()
	Retrieves the record from the relationship.

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord const *	operator-> () const
	Retrieves the record from the relationship.

LIGHTWEIGHT_FORCE_INLINE constexpr bool	operator! () const noexcept
	Checks if the field value is NULL.

LIGHTWEIGHT_FORCE_INLINE constexpr	operator bool () const noexcept
	Checks if the field value is not NULL.

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord &	EmplaceRecord ()
	Emplaces a record into the relationship. This will mark the relationship as loaded.

LIGHTWEIGHT_FORCE_INLINE void	BindOutputColumn (SQLSMALLINT outputIndex, SqlStatement &stmt)

template<auto OtherReferencedField>
std::weak_ordering	operator<=> (BelongsTo< OtherReferencedField > const &other) const noexcept

template<detail::FieldElementType T, PrimaryKey IsPrimaryKeyValue = PrimaryKey::No>
std::weak_ordering	operator<=> (Field< T, IsPrimaryKeyValue > const &other) const noexcept

template<auto OtherReferencedField>
bool	operator== (BelongsTo< OtherReferencedField > const &other) const noexcept

template<auto OtherReferencedField>
bool	operator!= (BelongsTo< OtherReferencedField > const &other) const noexcept

template<detail::FieldElementType T, PrimaryKey IsPrimaryKeyValue = PrimaryKey::No>
bool	operator== (Field< T, IsPrimaryKeyValue > const &other) const noexcept

template<detail::FieldElementType T, PrimaryKey IsPrimaryKeyValue = PrimaryKey::No>
bool	operator!= (Field< T, IsPrimaryKeyValue > const &other) const noexcept

void	SetAutoLoader (Loader loader) noexcept
	Used internally to configure on-demand loading of the record.

Static Public Attributes
static constexpr auto	ReferencedField = TheReferencedField
	The field in the other record that references the current record.

static constexpr std::string_view	ColumnNameOverride
	If not an empty string, this value will be used as the column name in the database.

static constexpr auto	IsOptional = true

static constexpr auto	IsMandatory = !IsOptional

static constexpr auto	IsPrimaryKey = false

static constexpr auto	IsAutoIncrementPrimaryKey = false

Detailed Description

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>
class BelongsTo< TheReferencedField, ColumnNameOverrideString >

Represents a one-to-one relationship.

The TheReferencedField parameter is the field in the other record that references the current record, in the form of &OtherRecord::Field. Other Field must be a primary key.

Template Parameters

TheReferencedField	The field in the other record that references the current record.
ColumnNameOverrideString	If not an empty string, this value will be used as the column name in the database.

struct User {
    Field<SqlGuid, PrimaryKey::AutoAssign> id;
    Field<SqlAnsiString<30>> name;
};
struct Email {
    Field<SqlGuid, PrimaryKey::AutoAssign> id;
    Field<SqlAnsiString<40>> address;
    BelongsTo<&User::id> user;
    BelongsTo<&User::id, SqlRealName<"the_user_id">> user; // also possible to customize the column name
};

Definition at line 41 of file BelongsTo.hpp.

Member Typedef Documentation

◆ ReferencedRecord

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

using BelongsTo< TheReferencedField, ColumnNameOverrideString >::ReferencedRecord = MemberClassType<decltype(TheReferencedField)>

Represents the record type of the other field.

Definition at line 58 of file BelongsTo.hpp.

◆ ValueType

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

using BelongsTo< TheReferencedField, ColumnNameOverrideString >::ValueType = typename std::remove_cvref_t<decltype(std::declval<ReferencedRecord>().*ReferencedField)>::ValueType

Represents the column type of the foreign key, matching the primary key of the other record.

Definition at line 64 of file BelongsTo.hpp.

Constructor & Destructor Documentation

◆ BelongsTo() [1/4]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

template<typename... S>
requires std::constructible_from<ValueType, S...>

constexpr BelongsTo< TheReferencedField, ColumnNameOverrideString >::BelongsTo ( S &&... value )

inlineconstexprnoexcept

Definition at line 73 of file BelongsTo.hpp.

◆ BelongsTo() [2/4]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

constexpr BelongsTo< TheReferencedField, ColumnNameOverrideString >::BelongsTo ( ReferencedRecord const & other )

inlineconstexprnoexcept

Definition at line 78 of file BelongsTo.hpp.

◆ BelongsTo() [3/4]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

constexpr BelongsTo< TheReferencedField, ColumnNameOverrideString >::BelongsTo ( SelfType const & other )

inlineconstexprnoexcept

Definition at line 85 of file BelongsTo.hpp.

◆ BelongsTo() [4/4]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

constexpr BelongsTo< TheReferencedField, ColumnNameOverrideString >::BelongsTo ( SelfType && other )

inlineconstexprnoexcept

Definition at line 94 of file BelongsTo.hpp.

Member Function Documentation

◆ operator=() [1/3]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

BelongsTo & BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator= ( SqlNullType )

inlinenoexcept

Definition at line 104 of file BelongsTo.hpp.

◆ operator=() [2/3]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

BelongsTo & BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator= ( ReferencedRecord & other )

inline

Definition at line 115 of file BelongsTo.hpp.

◆ operator=() [3/3]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

BelongsTo & BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator= ( SelfType const & other )

inline

Definition at line 126 of file BelongsTo.hpp.

◆ SetModified()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr void BelongsTo< TheReferencedField, ColumnNameOverrideString >::SetModified ( bool value )

inlineconstexprnoexcept

Marks the field as modified or unmodified.

Definition at line 143 of file BelongsTo.hpp.

◆ IsModified()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr bool BelongsTo< TheReferencedField, ColumnNameOverrideString >::IsModified ( ) const

inlineconstexprnoexcept

Checks if the field is modified.

Definition at line 146 of file BelongsTo.hpp.

◆ Value()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr ValueType const & BelongsTo< TheReferencedField, ColumnNameOverrideString >::Value ( ) const

inlineconstexprnoexcept

Retrieves the reference to the value of the field.

Definition at line 149 of file BelongsTo.hpp.

◆ MutableValue()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr ValueType & BelongsTo< TheReferencedField, ColumnNameOverrideString >::MutableValue ( )

inlineconstexprnoexcept

Retrieves the mutable reference to the value of the field.

Definition at line 152 of file BelongsTo.hpp.

◆ Record() [1/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord & BelongsTo< TheReferencedField, ColumnNameOverrideString >::Record ( )

inlineconstexpr

Retrieves a record from the relationship.

Definition at line 155 of file BelongsTo.hpp.

◆ Record() [2/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord const & BelongsTo< TheReferencedField, ColumnNameOverrideString >::Record ( ) const

inlineconstexpr

Retrieves an immutable reference to the record from the relationship.

Definition at line 158 of file BelongsTo.hpp.

◆ IsLoaded()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr bool BelongsTo< TheReferencedField, ColumnNameOverrideString >::IsLoaded ( ) const

inlineconstexprnoexcept

Checks if the record is loaded into memory.

Definition at line 161 of file BelongsTo.hpp.

◆ Unload()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE void BelongsTo< TheReferencedField, ColumnNameOverrideString >::Unload ( )

inlinenoexcept

Unloads the record from memory.

Definition at line 164 of file BelongsTo.hpp.

◆ operator*() [1/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord & BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator* ( )

inlineconstexprnoexcept

Retrieves the record from the relationship.

Definition at line 167 of file BelongsTo.hpp.

◆ operator*() [2/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord const & BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator* ( ) const

inlineconstexprnoexcept

Retrieves the record from the relationship.

Definition at line 170 of file BelongsTo.hpp.

◆ operator->() [1/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord * BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator-> ( )

inlineconstexpr

Retrieves the record from the relationship.

Definition at line 173 of file BelongsTo.hpp.

◆ operator->() [2/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord const * BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator-> ( ) const

inlineconstexpr

Retrieves the record from the relationship.

Definition at line 176 of file BelongsTo.hpp.

◆ operator!()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr bool BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator! ( ) const

inlineconstexprnoexcept

Checks if the field value is NULL.

Definition at line 179 of file BelongsTo.hpp.

◆ operator bool()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator bool ( ) const

inlineexplicitconstexprnoexcept

Checks if the field value is not NULL.

Definition at line 182 of file BelongsTo.hpp.

◆ EmplaceRecord()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE constexpr ReferencedRecord & BelongsTo< TheReferencedField, ColumnNameOverrideString >::EmplaceRecord ( )

inlineconstexpr

Emplaces a record into the relationship. This will mark the relationship as loaded.

Definition at line 187 of file BelongsTo.hpp.

◆ BindOutputColumn()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

LIGHTWEIGHT_FORCE_INLINE void BelongsTo< TheReferencedField, ColumnNameOverrideString >::BindOutputColumn	(	SQLSMALLINT	outputIndex,
		SqlStatement &	stmt
	)

inline

Definition at line 194 of file BelongsTo.hpp.

◆ operator<=>() [1/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

template<auto OtherReferencedField>

std::weak_ordering BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator<=> ( BelongsTo< OtherReferencedField > const & other ) const

inlinenoexcept

Definition at line 200 of file BelongsTo.hpp.

◆ operator<=>() [2/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

template<detail::FieldElementType T, PrimaryKey IsPrimaryKeyValue = PrimaryKey::No>

std::weak_ordering BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator<=> ( Field< T, IsPrimaryKeyValue > const & other ) const

inlinenoexcept

Definition at line 206 of file BelongsTo.hpp.

◆ operator==() [1/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

template<auto OtherReferencedField>

bool BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator== ( BelongsTo< OtherReferencedField > const & other ) const

inlinenoexcept

Definition at line 212 of file BelongsTo.hpp.

◆ operator!=() [1/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

template<auto OtherReferencedField>

bool BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator!= ( BelongsTo< OtherReferencedField > const & other ) const

inlinenoexcept

Definition at line 218 of file BelongsTo.hpp.

◆ operator==() [2/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

template<detail::FieldElementType T, PrimaryKey IsPrimaryKeyValue = PrimaryKey::No>

bool BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator== ( Field< T, IsPrimaryKeyValue > const & other ) const

inlinenoexcept

Definition at line 224 of file BelongsTo.hpp.

◆ operator!=() [2/2]

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

template<detail::FieldElementType T, PrimaryKey IsPrimaryKeyValue = PrimaryKey::No>

bool BelongsTo< TheReferencedField, ColumnNameOverrideString >::operator!= ( Field< T, IsPrimaryKeyValue > const & other ) const

inlinenoexcept

Definition at line 230 of file BelongsTo.hpp.

◆ SetAutoLoader()

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

void BelongsTo< TheReferencedField, ColumnNameOverrideString >::SetAutoLoader ( Loader loader )

inlinenoexcept

Used internally to configure on-demand loading of the record.

Definition at line 241 of file BelongsTo.hpp.

Member Data Documentation

◆ ReferencedField

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

constexpr auto BelongsTo< TheReferencedField, ColumnNameOverrideString >::ReferencedField = TheReferencedField

staticconstexpr

The field in the other record that references the current record.

Definition at line 47 of file BelongsTo.hpp.

◆ ColumnNameOverride

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

constexpr std::string_view BelongsTo< TheReferencedField, ColumnNameOverrideString >::ColumnNameOverride

staticconstexpr

Initial value:

= []() consteval {
        if constexpr (!std::same_as<decltype(ColumnNameOverrideString), std::nullopt_t>)
            return std::string_view { ColumnNameOverrideString };
        else
            return std::string_view {};
    }()

If not an empty string, this value will be used as the column name in the database.

Definition at line 50 of file BelongsTo.hpp.

◆ IsOptional

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

constexpr auto BelongsTo< TheReferencedField, ColumnNameOverrideString >::IsOptional = true

staticconstexpr

Definition at line 66 of file BelongsTo.hpp.

◆ IsMandatory

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

constexpr auto BelongsTo< TheReferencedField, ColumnNameOverrideString >::IsMandatory = !IsOptional

staticconstexpr

Definition at line 67 of file BelongsTo.hpp.

◆ IsPrimaryKey

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

constexpr auto BelongsTo< TheReferencedField, ColumnNameOverrideString >::IsPrimaryKey = false

staticconstexpr

Definition at line 68 of file BelongsTo.hpp.

◆ IsAutoIncrementPrimaryKey

template<auto TheReferencedField, auto ColumnNameOverrideString = std::nullopt>

constexpr auto BelongsTo< TheReferencedField, ColumnNameOverrideString >::IsAutoIncrementPrimaryKey = false

staticconstexpr

Definition at line 69 of file BelongsTo.hpp.

The documentation for this class was generated from the following file:

Lightweight/DataMapper/BelongsTo.hpp

Public Types

Public Member Functions

Static Public Attributes

Detailed Description

Member Typedef Documentation

◆ ReferencedRecord

◆ ValueType

Constructor & Destructor Documentation

◆ BelongsTo() [1/4]

◆ BelongsTo() [2/4]

◆ BelongsTo() [3/4]

◆ BelongsTo() [4/4]

Member Function Documentation

◆ operator=() [1/3]

◆ operator=() [2/3]

◆ operator=() [3/3]

◆ SetModified()

◆ IsModified()

◆ Value()

◆ MutableValue()

◆ Record() [1/2]

◆ Record() [2/2]

◆ IsLoaded()

◆ Unload()

◆ operator*() [1/2]

◆ operator*() [2/2]

◆ operator->() [1/2]

◆ operator->() [2/2]

◆ operator!()

◆ operator bool()

◆ EmplaceRecord()

◆ BindOutputColumn()

◆ operator<=>() [1/2]

◆ operator<=>() [2/2]

◆ operator==() [1/2]

◆ operator!=() [1/2]

◆ operator==() [2/2]

◆ operator!=() [2/2]

◆ SetAutoLoader()

Member Data Documentation

◆ ReferencedField

◆ ColumnNameOverride

◆ IsOptional

◆ IsMandatory

◆ IsPrimaryKey

◆ IsAutoIncrementPrimaryKey