index_info< T > Class Template Reference

Virtual Table Indexing Information. More...

Inheritance diagram for index_info< T >:

Public Types
using	constraint = sqlite3_index_info::sqlite3_index_constraint
	Alias for unwieldy C struct name.
using	constraint_usage = sqlite3_index_info::sqlite3_index_constraint_usage
	Alias for unwieldy C struct name.
using	orderby = sqlite3_index_info::sqlite3_index_orderby
	Alias for unwieldy C struct name.

Public Member Functions
span< const constraint >	constraints () const noexcept
	Returns the table of WHERE clause constraints.
span< const orderby >	orderbys () const noexcept
	Returns the table of ORDER BY clause constraints.
uint64_t	columns_used () const noexcept
	Returns mask of columns used by statement.
const char *	collation (int constraint_idx) const noexcept
	Determine the collation for a constraint.
int	distinct () const noexcept
	Determine if the query is DISTINCT.
bool	is_in (int constraint_idx) const noexcept
	Determine if a constraint is an IN that can be processed all at once.
void	handle_in (int constraint_idx, bool handle) const noexcept
	Set all-at-once processing of an IN operator.
span< const constraint_usage >	constraints_usage () const noexcept
	Returns the desired usage of the constraints.
span< constraint_usage >	constraints_usage () noexcept
	Returns the desired usage of the constraints.
int	index_number () const noexcept
	Returns number used to identify the index.
void	set_index_number (int val) noexcept
	Sets number used to identify the index.
T	index_data () const noexcept
	Returns data associated with the index.
template<class X >
void	set_index_data (X *data, bool allocated=false) noexcept
	Set the index data.
template<class X >
void	set_index_data (std::unique_ptr< X, sqlite_deleter< X > > data) noexcept
	Set the index data.
template<class X >
void	set_index_data (std::unique_ptr< X > data) noexcept
	Set the index data.
bool	order_by_consumed () const noexcept
	Returns whether the cursor output is already ordered.
void	set_order_by_consumed (bool val) noexcept
	Sets whether the cursor output is already ordered.
double	estimated_cost () const noexcept
	Returns estimated cost of using this index.
void	set_estimated_cost (double val) noexcept
	Sets estimated cost of using this index.
int64_t	estimated_rows () const noexcept
	Returns estimated number of rows returned.
void	set_estimated_rows (int64_t val) noexcept
	Sets estimated number of rows returned.
int	index_flags () const noexcept
	Returns mask of SQLITE_INDEX_SCAN_ flags.
void	set_index_flags (int val) noexcept
	Sets mask of SQLITE_INDEX_SCAN_ flags.
void	operator delete (void *) noexcept
	Operator delete for a fake pointer is no-op.
sqlite3_index_info *	c_ptr () const noexcept
	Access the real underlying SQLite type.

Static Public Member Functions
static index_info< void > *	from (sqlite3_index_info *obj) noexcept
	Create fake pointer from the underlying SQLite one.

Detailed Description

template<class T = void>
class thinsqlitepp::index_info< T >

Virtual Table Indexing Information.

This is a fake wrapper class for sqlite3_index_info.

It is used by your functions overriding vtab::best_index but can also be used standalone if manually implementing xBestIndex.

Unlike other SQLite data types sqlite3_index_info is a real struct, not an opaque data type. If desired you can directly access the struct members via c_ptr() but this wrapper provides convenient and safe inline accessor methods for all members.

Template Parameters

T	The type of the index data in sqlite3_index_info::idxStr. Must be a pointer or void. If void storing data is disabled.

#include <thinsqlitepp/vtab.hpp>

Member Function Documentation

columns_used()

template<class T = void>

uint64_t columns_used ( ) const

inlinenoexcept

Returns mask of columns used by statement.

Since

SQLite 3.10.0

collation()

template<class T = void>

const char * collation ( int constraint_idx ) const

inlinenoexcept

Determine the collation for a constraint.

Equivalent to sqlite3_vtab_collation

distinct()

template<class T = void>

int distinct ( ) const

inlinenoexcept

Determine if the query is DISTINCT.

Equivalent to sqlite3_vtab_distinct

is_in()

template<class T = void>

bool is_in ( int constraint_idx ) const

inlinenoexcept

Determine if a constraint is an IN that can be processed all at once.

Equivalent to sqlite3_vtab_in with last argument -1

handle_in()

template<class T = void>

void handle_in ( int constraint_idx, bool handle ) const

inlinenoexcept

Set all-at-once processing of an IN operator.

Equivalent to sqlite3_vtab_in

constraints_usage() [1/2]

template<class T = void>

span< const constraint_usage > constraints_usage ( ) const

inlinenoexcept

Returns the desired usage of the constraints.

The size of this span is the same as returned by constraints.

constraints_usage() [2/2]

template<class T = void>

span< constraint_usage > constraints_usage ( )

inlinenoexcept

Returns the desired usage of the constraints.

The size of this span is the same as returned by constraints.

index_data()

template<class T = void>

T index_data ( ) const

inlinenoexcept

Returns data associated with the index.

Only meaningful if template parameter T is non-void. Otherwise does nothing and returns nothing.

set_index_data() [1/3]

template<class T = void>

template<class X >

void set_index_data ( X * data, bool allocated = false )

inlinenoexcept

Set the index data.

Enabled only if template parameter T is non-void and data pointer can be converted to it.

Parameters

data	data to set
allocated	if true SQLite will automatically free the data using sqlite3_free. Otherwise you are responsible for the pointed data lifecycle

set_index_data() [2/3]

template<class T = void>

template<class X >

void set_index_data ( std::unique_ptr< X, sqlite_deleter< X > > data )

inlinenoexcept

Set the index data.

This is a convenience overload of set_index_data(T, bool) that takes a std::unique_pointer with an sqlite_deleter.

Enabled only if template parameter T is non-void, trivially destructible and data pointer type can be converted to it.

set_index_data() [3/3]

template<class T = void>

template<class X >

void set_index_data ( std::unique_ptr< X > data )

inlinenoexcept

Set the index data.

This is a convenience overload of set_index_data(T *, bool) that takes a std::unique_pointer to T.

Enabled only if template parameter T is a pointer to a trivially destructible class derived from sqlite_allocated

estimated_rows()

template<class T = void>

int64_t estimated_rows ( ) const

inlinenoexcept

Returns estimated number of rows returned.

Since

SQLite 3.8.2

set_estimated_rows()

template<class T = void>

void set_estimated_rows ( int64_t val )

inlinenoexcept

Sets estimated number of rows returned.

Since

SQLite 3.8.2

index_flags()

template<class T = void>

int index_flags ( ) const

inlinenoexcept

Returns mask of SQLITE_INDEX_SCAN_ flags.

Since

SQLite 3.9.0

set_index_flags()

template<class T = void>

void set_index_flags ( int val )

inlinenoexcept

Sets mask of SQLITE_INDEX_SCAN_ flags.

Since

SQLite 3.9.0