A field that stores a JSON value. More...

#include <field.h>

Inheritance diagram for Field_json:

Public Member Functions
	Field_json (uchar ptr_arg, uchar null_ptr_arg, uint null_bit_arg, uchar auto_flags_arg, const char field_name_arg, TABLE_SHARE share, uint blob_pack_length)

	Field_json (uint32 len_arg, bool is_nullable_arg, const char *field_name_arg)

enum_field_types	type () const override

void	sql_type (String &str) const override
	Get the type of this field (json). More...

const CHARSET_INFO *	charset () const override
	Return a text charset so that string functions automatically convert the field value to string and treat it as a non-binary string. More...

const CHARSET_INFO *	sort_charset () const final
	Sort should treat the field as binary and not attempt any conversions. More...

bool	has_charset () const final
	JSON columns don't have an associated charset. More...

type_conversion_status	store (const char to, size_t length, const CHARSET_INFO charset) override
	Store data in this JSON field. More...

type_conversion_status	store (double nr) override
	Store a double in a JSON field. Will raise an error for now. More...

type_conversion_status	store (longlong nr, bool unsigned_val) override
	Store an integer in a JSON field. Will raise an error for now. More...

type_conversion_status	store_decimal (const my_decimal *) final
	Store a decimal in a JSON field. Will raise an error for now. More...

type_conversion_status	store_json (const Json_wrapper *json)
	Store a JSON value as binary. More...

type_conversion_status	store_time (MYSQL_TIME *ltime, uint8 dec_arg) final
	Store a TIME value in a JSON field. Will raise an error for now. More...

type_conversion_status	store (const Field_json *field)
	Copy the contents of a non-null JSON field into this field. More...

bool	pack_diff (uchar **to, ulonglong value_options) const final
	Write the field for the binary log in diff format. More...

longlong	get_diff_vector_and_length (ulonglong value_options, const Json_diff_vector **diff_vector_p=nullptr) const
	Return the length of this field, taking into consideration that it may be in partial format. More...

bool	is_before_image_equal_to_after_image () const
	Return true if the before-image and after-image for this field are equal. More...

bool	unpack_diff (const uchar **from)
	Read the binary diff from the given buffer, and apply it to this field. More...

bool	val_json (Json_wrapper *wr) const
	Retrieve the field's value as a JSON wrapper. More...

longlong	val_int () const final
	Retrieve the JSON as an int if possible. More...

double	val_real () const final
	Retrieve the JSON as a double if possible. More...

String *	val_str (String buf1, String buf2) const final
	Retrieve the JSON value stored in this field as text. More...

my_decimal *	val_decimal (my_decimal *m) const final

bool	get_time (MYSQL_TIME *ltime) const final

bool	get_date (MYSQL_TIME *ltime, my_time_flags_t fuzzydate) const final

Field_json *	clone (MEM_ROOT *mem_root) const override
	Create a shallow clone of this field in the specified MEM_ROOT. More...

uint	is_equal (const Create_field *new_field) const final
	Check if a new field is compatible with this one. More...

Item_result	cast_to_int_type () const final

int	cmp_binary (const uchar a, const uchar b, uint32 max_length=~0L) const final

size_t	make_sort_key (uchar *to, size_t length) const override
	Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison. More...

ulonglong	make_hash_key (ulonglong hash_val) const
	Make a hash key that can be used by sql_executor.cc/unique_hash in order to support SELECT DISTINCT. More...

const char *	get_binary (ptrdiff_t row_offset=0) const
	Get a read-only pointer to the binary representation of the JSON document in this field. More...

size_t	make_sort_key (uchar *buff, size_t length) const override
	Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison. More...

size_t	make_sort_key (uchar *to, size_t length, size_t trunc_pos) const final
	Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison. More...

Public Member Functions inherited from Field_blob
	Field_blob (uchar ptr_arg, uchar null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char field_name_arg, TABLE_SHARE share, uint blob_pack_length, const CHARSET_INFO *cs)

	Field_blob (uint32 len_arg, bool is_nullable_arg, const char field_name_arg, const CHARSET_INFO cs, bool set_packlength)

	Field_blob (const Field_blob &field)
	Copy static information and reset dynamic information. More...

	Field_blob (uint32 packlength_arg)

bool	match_collation_to_optimize_range () const override

enum ha_base_keytype	key_type () const override

type_conversion_status	store (const Field *from)

int	cmp_max (const uchar , const uchar , uint max_length) const final

int	cmp (const uchar a, const uchar b) const final

int	cmp (const uchar a, uint32 a_length, const uchar b, uint32 b_length) const

int	key_cmp (const uchar , const uchar ) const override

int	key_cmp (const uchar *str, uint length) const override

uint32	key_length () const override

uint32	pack_length () const final

uint32	pack_length_no_ptr () const
	Return the packed length without the pointer size added. More...

uint	row_pack_length () const final

uint32	max_data_length () const final
	Get the maximum size of the data in packed format. More...

size_t	get_field_buffer_size ()

void	store_length (uchar *i_ptr, uint i_packlength, uint32 i_number)

void	store_length (uint32 number)

uint32	data_length (ptrdiff_t row_offset=0) const final

uint32	get_length (ptrdiff_t row_offset=0) const

uint32	get_length (const uchar *ptr, uint packlength) const

uint32	get_length (const uchar *ptr_arg) const

const uchar *	get_blob_data () const
	Get a const pointer to the BLOB data of this field. More...

uchar *	get_blob_data (ptrdiff_t row_offset=0)
	Get a non-const pointer to the BLOB data of this field. More...

const uchar *	data_ptr () const final
	Get a const pointer to the BLOB data of this field. More...

void	set_ptr (const uchar length, const uchar data)

void	set_ptr_offset (ptrdiff_t ptr_diff, uint32 length, const uchar *data)

void	set_ptr (uint32 length, const uchar *data)

size_t	get_key_image (uchar *buff, size_t length, imagetype type) const override

void	set_key_image (const uchar *buff, size_t length) final

bool	copy ()

uchar *	pack (uchar to, const uchar from, size_t max_length) const final
	Pack the field into a format suitable for storage and transfer. More...

uchar *	pack_with_metadata_bytes (uchar to, const uchar from, uint max_length) const final
	This function does the same thing as pack(), except for the difference that max_length does not mean the number of bytes in the output, but the maximum field length from the input (which must be exactly field->max_field_length()). More...

const uchar *	unpack (uchar , const uchar from, uint param_data) final
	Unpack a blob field from row data. More...

uint	max_packed_col_length () const final
	This is a wrapper around pack_length() used by filesort() to determine how many bytes we need for packing "addon fields". More...

void	mem_free () final

uint32	max_display_length () const final
	maximum possible display length for blob. More...

uint32	char_length () const override
	maximum possible character length for blob. More...

bool	copy_blob_value (MEM_ROOT *mem_root)
	This function creates a separate copy of blob value. More...

bool	is_text_key_type () const final

void	set_keep_old_value (bool old_value_flag)
	Mark that the BLOB stored in value should be copied before updating it. More...

void	keep_old_value ()
	Save the current BLOB value to avoid that it gets overwritten. More...

void	store_in_allocated_space (const char *from, uint32 length)
	Use to store the blob value into an allocated space. More...

bool	backup_blob_field ()
	Backup data stored in 'value' into the backup_value. More...

void	restore_blob_backup ()
	Restore backup value. More...

Public Member Functions inherited from Field_longstr
	Field_longstr (uchar ptr_arg, uint32 len_arg, uchar null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char field_name_arg, const CHARSET_INFO charset_arg)

bool	is_updatable () const final
	Checks whether a string field is part of write_set. More...

Public Member Functions inherited from Field_str
	Field_str (uchar ptr_arg, uint32 len_arg, uchar null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char field_name_arg, const CHARSET_INFO charset)

Item_result	result_type () const override

Item_result	numeric_context_result_type () const final
	Returns Item_result type of a field when it appears in numeric context such as: SELECT time_column + 1; SELECT SUM(time_column); Examples: More...

uint	decimals () const override

void	make_send_field (Send_field *field) const override
	Populates a Send_field object with metadata about the column represented by this Field object. More...

uint	repertoire () const final

void	set_charset (const CHARSET_INFO *charset_arg)

void	set_field_length (uint32 length) final

enum Derivation	derivation () const final

void	set_derivation (enum Derivation derivation_arg) final

bool	binary () const override

bool	str_needs_quotes () const final

Public Member Functions inherited from Field
	Field (const Field &)=default

void	operator= (Field &)=delete

bool	has_insert_default_general_value_expression () const
	Checks if the field is marked as having a general expression to generate default values. More...

bool	has_insert_default_datetime_value_expression () const
	Checks if the field is marked as having a datetime value expression to generate default values on inserts. More...

bool	has_update_default_datetime_value_expression () const
	Checks if the field is marked as having a datetime value expression to generate default values on updates. More...

bool	has_insert_default_constant_expression () const
	Checks if the field is marked as having a constant expression to generate default values. More...

uchar *	get_null_ptr ()

bool	is_flag_set (unsigned flag) const

void	set_flag (unsigned flag)

void	clear_flag (unsigned flag)

uint32	all_flags () const

virtual bool	is_wrapper_field () const
	If true, it's a Create_field_wrapper (a sub-class of Field used during CREATE/ALTER that we mustn't cast to other sub-classes of Field that aren't on a direct path of inheritance, e.g. More...

virtual bool	is_unsigned () const
	Whether the field is signed or not. More...

bool	is_gcol () const

bool	is_virtual_gcol () const

void	set_hidden (dd::Column::enum_hidden_type hidden)
	Sets the hidden type for this field. More...

dd::Column::enum_hidden_type	hidden () const

bool	is_hidden () const

bool	is_hidden_by_system () const

bool	is_hidden_by_user () const

bool	is_field_for_functional_index () const

	Field (uchar ptr_arg, uint32 length_arg, uchar null_ptr_arg, uchar null_bit_arg, uchar auto_flags_arg, const char *field_name_arg)
	This is used as a table name when the table structure is not set up. More...

virtual	~Field ()=default

void	reset_warnings ()

void	set_tmp_nullable ()
	Turn on temporary nullability for the field. More...

void	reset_tmp_nullable ()
	Turn off temporary nullability for the field. More...

void	reset_tmp_null ()
	Reset temporary NULL value for field. More...

void	set_tmp_null ()
	Set field to temporary value NULL. More...

bool	is_tmp_nullable () const

bool	is_tmp_null () const

virtual type_conversion_status	store_packed (longlong nr)
	Store a temporal value in packed longlong format into a field. More...

type_conversion_status	store_time (MYSQL_TIME *ltime)
	Store MYSQL_TYPE value into a field when the number of fractional digits is not important or is not know. More...

type_conversion_status	store (const char to, size_t length, const CHARSET_INFO cs, enum_check_fields check_level)

virtual longlong	val_time_temporal () const
	Returns TIME value in packed longlong format. More...

virtual longlong	val_date_temporal () const
	Returns DATE/DATETIME value in packed longlong format. More...

virtual longlong	val_time_temporal_at_utc () const

virtual longlong	val_date_temporal_at_utc () const

longlong	val_temporal_by_field_type () const
	Returns "native" packed longlong representation of a TIME or DATE/DATETIME field depending on field type. More...

String *	val_str (String *str) const

String *	val_int_as_str (String *val_buffer, bool unsigned_flag) const
	Interpret field value as an integer but return the result as a string. More...

virtual Item_result	cmp_type () const

bool	gcol_expr_is_equal (const Create_field *field) const
	Check whether generated columns' expressions are the same. More...

virtual bool	eq (const Field *field) const

virtual bool	eq_def (const Field *field) const

virtual uint32	pack_length_in_rec () const

virtual bool	compatible_field_size (uint metadata, Relay_log_info , uint16, int order) const
	Check to see if field size is compatible with destination. More...

virtual uint	pack_length_from_metadata (uint field_metadata) const

int	save_field_metadata (uchar *first_byte)

virtual type_conversion_status	reset ()

virtual bool	get_timestamp (my_timeval tm, int warnings) const
	Returns a UTC component in `struct timeval` format. More...

virtual void	store_timestamp (const my_timeval *)
	Stores a timestamp value in timeval format in a field. More...

virtual void	set_default ()

void	evaluate_insert_default_function ()
	Evaluates the `INSERT` default function and stores the result in the field. More...

void	evaluate_update_default_function ()
	Evaluates the `UPDATE` default function, if one exists, and stores the result in the record buffer. More...

virtual bool	zero_pack () const

virtual enum_field_types	real_type () const

virtual enum_field_types	binlog_type () const

int	cmp (const uchar *str) const

virtual int	cmp_offset (ptrdiff_t row_offset) const

virtual int	cmp_binary_offset (ptrdiff_t row_offset) const

bool	is_null (ptrdiff_t row_offset=0) const
	Check whether the full table's row is NULL or the Field has value NULL. More...

bool	is_real_null (ptrdiff_t row_offset=0) const
	Check whether the Field has value NULL (temporary or actual). More...

bool	is_null_in_record (const uchar *record) const
	Check if the Field has value NULL or the record specified by argument has value NULL for this Field. More...

void	set_null (ptrdiff_t row_offset=0)
	Set field to value NULL. More...

void	set_notnull (ptrdiff_t row_offset=0)
	Set field to value NOT NULL. More...

type_conversion_status	check_constraints (int mysql_errno)
	Check NOT NULL constraint on the field after temporary nullability is disabled. More...

void	set_check_for_truncated_fields (enum_check_fields check_for_truncated_fields)
	Remember the value of THD::check_for_truncated_fields to handle possible NOT-NULL constraint errors after BEFORE-trigger execution is finished. More...

bool	is_nullable () const

uint	null_offset (const uchar *record) const

uint	null_offset () const

void	set_null_ptr (uchar *p_null_ptr, uint p_null_bit)

virtual bool	optimize_range (uint idx, uint part) const
	Whether this field can be used for index range scans when in the given keypart of the given index. More...

virtual bool	can_be_compared_as_longlong () const

virtual Field *	new_field (MEM_ROOT root, TABLE new_table) const

Field *	new_field (MEM_ROOT root, TABLE new_table, uchar new_ptr, uchar new_null_ptr, uint new_null_bit) const

virtual Field *	new_key_field (MEM_ROOT root, TABLE new_table, uchar new_ptr, uchar new_null_ptr, uint new_null_bit) const

Field *	new_key_field (MEM_ROOT root, TABLE new_table, uchar *new_ptr) const

void	move_field (uchar ptr_arg, uchar null_ptr_arg, uchar null_bit_arg)

virtual void	move_field_offset (ptrdiff_t ptr_diff)

virtual void	get_image (uchar buff, size_t length, const CHARSET_INFO ) const

virtual void	set_image (const uchar buff, size_t length, const CHARSET_INFO )

longlong	val_int_offset (ptrdiff_t row_offset)

longlong	val_int (uchar *new_ptr)

String *	val_str (String str, uchar new_ptr)

virtual bool	send_to_protocol (Protocol *protocol) const
	Send the value of this field over the protocol using the correct Protocol::store*() function which matches the type of the field. More...

uchar *	pack (uchar *to) const

const uchar *	unpack (const uchar *from)

uint	offset (uchar *record) const

void	copy_data (ptrdiff_t src_record_offset)

const CHARSET_INFO *	charset_for_protocol () const

bool	set_warning (Sql_condition::enum_severity_level level, unsigned int code, int cut_increment)
	Produce warning or note about data saved into field. More...

bool	set_warning (Sql_condition::enum_severity_level level, uint code, int cut_increment, const char view_db, const char view_name)
	Produce warning or note about data saved into field. More...

bool	warn_if_overflow (int op_result)
	Process decimal library return codes and issue warnings for overflow and truncation. More...

virtual void	init (TABLE *table_arg)

longlong	convert_decimal2longlong (const my_decimal val, bool unsigned_flag, bool has_overflow)
	Conversion from decimal to longlong. More...

virtual geometry_type	get_geometry_type () const

void	dbug_print () const

ha_storage_media	field_storage_type () const

void	set_storage_type (ha_storage_media storage_type_arg)

column_format_type	column_format () const

void	set_column_format (column_format_type column_format_arg)

virtual type_conversion_status	validate_stored_val (THD *thd)

virtual void	hash (ulong nr, ulong nr2) const

virtual ulonglong	get_max_int_value () const
	Get the upper limit of the MySQL integral and floating-point type. More...

const uchar *	field_ptr () const
	Return a const pointer to where the field is stored in the record buffer. More...

uchar *	field_ptr ()
	Return a pointer to where the field is stored in the record buffer. More...

void	set_field_ptr (uchar *ptr_arg)

bool	is_part_of_actual_key (THD thd, uint cur_index, KEY cur_index_info) const
	Check whether field is part of the index taking the index extensions flag into account. More...

Key_map	get_covering_prefix_keys () const
	Get covering prefix keys. More...

virtual bool	is_array () const
	Whether the field is a typed array. More...

virtual uint32	get_length_bytes () const
	Return number of bytes the field's length takes. More...

bool	handle_old_value () const
	Whether field's old valued have to be handled. More...

virtual void	set_field_index (uint16 field_index)
	Sets field index. More...

uint16	field_index () const
	Returns field index. More...

Private Member Functions
type_conversion_status	unsupported_conversion ()
	Helper function for raising an error when trying to store a value into a JSON column, and that value needs to be cast to JSON before it can be stored. More...

type_conversion_status	store_binary (const char *ptr, size_t length)
	Store the provided JSON binary data in this field. More...

Additional Inherited Members
Public Types inherited from Field
enum	enum_auto_flags { NONE = 0 , NEXT_NUMBER = 1 , DEFAULT_NOW = 2 , ON_UPDATE_NOW = 4 , GENERATED_FROM_EXPRESSION = 8 }
	Flags for Field::auto_flags / Create_field::auto_flags bitmaps. More...

enum	geometry_type { GEOM_GEOMETRY = 0 , GEOM_POINT = 1 , GEOM_LINESTRING = 2 , GEOM_POLYGON = 3 , GEOM_MULTIPOINT = 4 , GEOM_MULTILINESTRING = 5 , GEOM_MULTIPOLYGON = 6 , GEOM_GEOMETRYCOLLECTION = 7 }

enum	imagetype { itRAW , itMBR }

Static Public Member Functions inherited from Field
static bool	type_can_have_key_part (enum_field_types)
	Check whether a field type can be partially indexed by a key. More...

static enum_field_types	field_type_merge (enum_field_types, enum_field_types)
	Return type of which can carry value of both given types in UNION result. More...

static Item_result	result_merge_type (enum_field_types)
	Detect Item_result by given field type of UNION merge result. More...

Public Attributes inherited from Field_str
uint32	char_length_cache

Public Attributes inherited from Field
TABLE *	table
	Pointer to TABLE object that owns this field. More...

const char *	orig_db_name {nullptr}
	Pointer to original database name, only non-NULL for a temporary table. More...

const char *	orig_table_name {nullptr}
	Pointer to original table name, only non-NULL for a temporary table. More...

const char **	table_name

const char *	field_name

LEX_CSTRING	comment

Key_map	key_start

Key_map	part_of_key
	Keys that includes this field except of prefix keys. More...

Key_map	part_of_prefixkey
	Prefix keys. More...

Key_map	part_of_sortkey

Key_map	part_of_key_not_extended
	All keys that include this field, but not extended by the storage engine to include primary key columns. More...

uint32	field_length

uchar	null_bit

uchar	auto_flags
	Bitmap of flags indicating if field value is auto-generated by default and/or on update, and in which way. More...

bool	is_created_from_null_item
	If true, this field was created in create_tmp_field_from_item from a NULL value. More...

bool	m_indexed
	True if this field belongs to some index (unlike part_of_key, the index might have only a prefix). More...

LEX_CSTRING	m_engine_attribute = EMPTY_CSTR

LEX_CSTRING	m_secondary_engine_attribute = EMPTY_CSTR

Value_generator *	gcol_info {nullptr}

bool	stored_in_db
	Indication that the field is physically stored in tables rather than just generated on SQL queries. More...

Value_generator *	m_default_val_expr {nullptr}
	Holds the expression to be used to generate default values. More...

Static Public Attributes inherited from Field
static constexpr size_t	MAX_VARCHAR_WIDTH {65535}

static constexpr size_t	MAX_TINY_BLOB_WIDTH {255}

static constexpr size_t	MAX_SHORT_BLOB_WIDTH {65535}

static constexpr size_t	MAX_MEDIUM_BLOB_WIDTH {16777215}

static constexpr size_t	MAX_LONG_BLOB_WIDTH {4294967295}

Protected Member Functions inherited from Field_blob
void	store_ptr_and_length (const char *from, uint32 length)
	Store ptr and length. More...

Protected Member Functions inherited from Field_longstr
type_conversion_status	check_string_copy_error (const char well_formed_error_pos, const char cannot_convert_error_pos, const char from_end_pos, const char end, bool count_spaces, const CHARSET_INFO *cs)
	Report "not well formed" or "cannot convert" error after storing a character string info a field. More...

Protected Member Functions inherited from Field
uchar *	pack_int16 (uchar to, const uchar from, size_t max_length) const

const uchar *	unpack_int16 (uchar to, const uchar from) const

uchar *	pack_int24 (uchar to, const uchar from, size_t max_length) const

const uchar *	unpack_int24 (uchar to, const uchar from) const

uchar *	pack_int32 (uchar to, const uchar from, size_t max_length) const

const uchar *	unpack_int32 (uchar to, const uchar from) const

uchar *	pack_int64 (uchar to, const uchar from, size_t max_length) const

const uchar *	unpack_int64 (uchar to, const uchar from) const

Static Protected Member Functions inherited from Field_blob
static uchar *	get_blob_data (const uchar *position)
	Get the BLOB data pointer stored at the specified position in the record buffer. More...

Protected Attributes inherited from Field_blob
uint	packlength
	The number of bytes used to represent the length of the blob. More...

String	value
	The 'value'-object is a cache fronting the storage engine. More...

Protected Attributes inherited from Field_str
const CHARSET_INFO *	field_charset

enum Derivation	field_derivation

Protected Attributes inherited from Field
uchar *	ptr
	Holds the position to the field in record. More...

Static Protected Attributes inherited from Field
static uchar	dummy_null_buffer = ' '

Detailed Description

A field that stores a JSON value.

Constructor & Destructor Documentation

◆ Field_json() [1/2]

Field_json::Field_json	(	uchar *	ptr_arg,
		uchar *	null_ptr_arg,
		uint	null_bit_arg,
		uchar	auto_flags_arg,
		const char *	field_name_arg,
		TABLE_SHARE *	share,
		uint	blob_pack_length
	)

inline

◆ Field_json() [2/2]

Field_json::Field_json	(	uint32	len_arg,
		bool	is_nullable_arg,
		const char *	field_name_arg
	)

inline

Member Function Documentation

◆ cast_to_int_type()

Item_result Field_json::cast_to_int_type ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ charset()

const CHARSET_INFO * Field_json::charset ( ) const

inlineoverridevirtual

Return a text charset so that string functions automatically convert the field value to string and treat it as a non-binary string.

Reimplemented from Field_str.

Reimplemented in Field_typed_array.

◆ clone()

Field_json * Field_json::clone ( MEM_ROOT * mem_root ) const

overridevirtual

Create a shallow clone of this field in the specified MEM_ROOT.

Reimplemented from Field_blob.

Reimplemented in Field_typed_array.

◆ cmp_binary()

int Field_json::cmp_binary	(	const uchar *	a,
		const uchar *	b,
		uint32	max_length = `~0L`
	)		const

finalvirtual

Reimplemented from Field_blob.

◆ get_binary()

const char * Field_json::get_binary ( ptrdiff_t row_offset = 0 ) const

Get a read-only pointer to the binary representation of the JSON document in this field.

Parameters

row_offset Field's data offset

◆ get_date()

bool Field_json::get_date	(	MYSQL_TIME *	ltime,
		my_time_flags_t	fuzzydate
	)		const

finalvirtual

Reimplemented from Field.

◆ get_diff_vector_and_length()

longlong Field_json::get_diff_vector_and_length	(	ulonglong	value_options,
		const Json_diff_vector **	diff_vector_p = `nullptr`
	)		const

Return the length of this field, taking into consideration that it may be in partial format.

This is the format used when writing the binary log in row format and using a partial format according to @session.binlog_row_value_options.

Parameters

[in]	value_options	The value of binlog_row_value options.
[out]	diff_vector_p	If this is not NULL, the pointer it points to will be set to NULL if the field is to be stored in full format, or to the Json_diff_vector if the field is to be stored in partial format.

Returns: The number of bytes needed when writing to the binlog: the size of the full format if stored in full format and the size of the diffs if stored in partial format.

◆ get_time()

bool Field_json::get_time ( MYSQL_TIME * ltime ) const

finalvirtual

Reimplemented from Field.

◆ has_charset()

bool Field_json::has_charset ( ) const

inlinefinalvirtual

JSON columns don't have an associated charset.

Returning false here prevents SHOW CREATE TABLE from attaching a CHARACTER SET clause to the column.

Reimplemented from Field_blob.

◆ is_before_image_equal_to_after_image()

bool Field_json::is_before_image_equal_to_after_image ( ) const

Return true if the before-image and after-image for this field are equal.

◆ is_equal()

uint Field_json::is_equal ( const Create_field * new_field ) const

finalvirtual

Check if a new field is compatible with this one.

Parameters

new_field the new field

Returns: true if new_field is compatible with this field, false otherwise

Reimplemented from Field_blob.

◆ make_hash_key()

ulonglong Field_json::make_hash_key ( ulonglong hash_val ) const

Make a hash key that can be used by sql_executor.cc/unique_hash in order to support SELECT DISTINCT.

Parameters

[in] hash_val An initial hash value.

◆ make_sort_key() [1/3]

size_t Field_blob::make_sort_key	(	uchar *	buff,
		size_t	length
	)		const

overridevirtual

Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison.

Integers are always in big-endian regardless of hardware architecture. At most length bytes are written into the buffer.

Parameters

buff	The buffer, assumed to be at least length bytes.
length	Number of bytes to write.

Return values

The	number of bytes actually written.

Note: This is now only used by replication; filesort makes its own sort keys based off of Items, not Fields.

Reimplemented from Field_blob.

Reimplemented in Field_typed_array, and Field_typed_array.

◆ make_sort_key() [2/3]

size_t Field_json::make_sort_key	(	uchar *	buff,
		size_t	length
	)		const

overridevirtual

Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison.

Integers are always in big-endian regardless of hardware architecture. At most length bytes are written into the buffer.

Parameters

buff	The buffer, assumed to be at least length bytes.
length	Number of bytes to write.

Return values

The	number of bytes actually written.

Note: This is now only used by replication; filesort makes its own sort keys based off of Items, not Fields.

Reimplemented from Field_blob.

Reimplemented in Field_typed_array, Field_typed_array, and Field_typed_array.

◆ make_sort_key() [3/3]

size_t Field_blob::make_sort_key	(	uchar *	buff,
		size_t	length,
		size_t	trunc_pos
	)		const

finalvirtual

Writes a copy of the current value in the record buffer, suitable for sorting using byte-by-byte comparison.

Integers are always in big-endian regardless of hardware architecture. At most length bytes are written into the buffer. Field_string, Field_varstring and Field_blob classes are truncated after pos number of characters.

Parameters

buff	The buffer, assumed to be at least length bytes.
length	Number of bytes to write.
trunc_pos	Number of characters which should be included before truncation.

Return values

The	number of bytes actually written.

Note: This is now only used by replication; filesort makes its own sort keys based off of Items, not Fields.

Reimplemented from Field_blob.

Reimplemented in Field_typed_array.

◆ pack_diff()

bool Field_json::pack_diff	(	uchar **	to,
		ulonglong	value_options
	)		const

finalvirtual

Write the field for the binary log in diff format.

This should only write the field if the diff format is smaller than the full format. Otherwise it should leave the buffer untouched.

Parameters

[in,out]	to	Pointer to buffer where the field will be written. This will be changed to point to the next byte after the last byte that was written.
	value_options	bitmap that indicates if full or partial JSON format is to be used.

Return values

true	The field was not written, either because the data type does not support it, or because it was disabled according to value_options, or because there was no diff information available from the optimizer, or because the the diff format was bigger than the full format. The 'to' parameter is unchanged in this case.
false	The field was written.

Reimplemented from Field.

◆ sort_charset()

const CHARSET_INFO * Field_json::sort_charset ( ) const

inlinefinalvirtual

Sort should treat the field as binary and not attempt any conversions.

Reimplemented from Field.

◆ sql_type()

void Field_json::sql_type ( String & str ) const

overridevirtual

Get the type of this field (json).

Parameters

str	the string that receives the type

Reimplemented from Field_blob.

Reimplemented in Field_typed_array.

◆ store() [1/4]

type_conversion_status Field_json::store	(	const char *	from,
		size_t	length,
		const CHARSET_INFO *	cs
	)

overridevirtual

Store data in this JSON field.

JSON data is usually stored using store(Field_json*) or store_json(), so this function will only be called if non-JSON data is attempted stored in a JSON field. This results in an error in most cases.

It will attempt to parse the string (unless it's binary) as JSON text, and store a binary representation of JSON document if the string could be parsed.

Note that we override store() and not store_internal() because Field_blob::store() contains logic that bypasses store_internal() in some cases we care about. In particular:

When supplied an empty string, we want to raise a JSON syntax error instead of silently inserting an empty byte string.
When called from GROUP_CONCAT with ORDER BY or DISTINCT, we want to do the same data conversion as usual, whereas Field_blob::store() jumps directly to Field_blob::store_to_mem() with the unprocessed input data.

Parameters

from	the start of the data to be stored
length	the length of the data
cs	the character set of the data

Returns: zero on success, non-zero on failure

Reimplemented from Field_blob.

Reimplemented in Field_typed_array.

◆ store() [2/4]

type_conversion_status Field_json::store ( const Field_json * field )

Copy the contents of a non-null JSON field into this field.

Parameters

[in] field the field to copy data from

Returns: zero on success, non-zero on failure

◆ store() [3/4]

type_conversion_status Field_json::store ( double nr )

overridevirtual

Store a double in a JSON field. Will raise an error for now.

Reimplemented from Field_blob.

Reimplemented in Field_typed_array.

◆ store() [4/4]

type_conversion_status Field_json::store	(	longlong	nr,
		bool	unsigned_val
	)

overridevirtual

Store an integer in a JSON field. Will raise an error for now.

Reimplemented from Field_blob.

Reimplemented in Field_typed_array.

◆ store_binary()

type_conversion_status Field_json::store_binary	(	const char *	data,
		size_t	length
	)

private

Store the provided JSON binary data in this field.

Parameters

[in]	data	pointer to JSON binary data
[in]	length	the length of the binary data

Returns: zero on success, non-zero on failure

◆ store_decimal()

type_conversion_status Field_json::store_decimal ( const my_decimal * )

finalvirtual

Store a decimal in a JSON field. Will raise an error for now.

Reimplemented from Field_longstr.

◆ store_json()

type_conversion_status Field_json::store_json ( const Json_wrapper * json )

Store a JSON value as binary.

Parameters

json	the JSON value to store

Returns: zero on success, non-zero otherwise

◆ store_time()

type_conversion_status Field_json::store_time	(	MYSQL_TIME *	ltime,
		uint8	dec_arg
	)

finalvirtual

Store a TIME value in a JSON field. Will raise an error for now.

Reimplemented from Field.

◆ type()

enum_field_types Field_json::type ( ) const

inlineoverridevirtual

Reimplemented from Field_blob.

Reimplemented in Field_typed_array.

◆ unpack_diff()

bool Field_json::unpack_diff ( const uchar ** from )

Read the binary diff from the given buffer, and apply it to this field.

Parameters

[in,out] from Pointer to buffer where the binary diff is stored. This will be changed to point to the next byte after the field.

Return values

false	Success
true	Error (e.g. failed to apply the diff). The error has been reported through my_error.

◆ unsupported_conversion()

type_conversion_status Field_json::unsupported_conversion ( )

private

Helper function for raising an error when trying to store a value into a JSON column, and that value needs to be cast to JSON before it can be stored.

◆ val_decimal()

my_decimal * Field_json::val_decimal ( my_decimal * m ) const

finalvirtual

Reimplemented from Field_blob.

◆ val_int()

longlong Field_json::val_int ( void ) const

finalvirtual

Retrieve the JSON as an int if possible.

This requires a JSON scalar of suitable type.

Returns: the JSON value as an int

Reimplemented from Field_blob.

◆ val_json()

bool Field_json::val_json ( Json_wrapper * wr ) const

Retrieve the field's value as a JSON wrapper.

It there is an error, wr is not modified and we return false, else true.

Parameters

[out] wr the JSON value

Returns: true if a value is retrieved (or NULL), false if error

◆ val_real()

double Field_json::val_real ( void ) const

finalvirtual

Retrieve the JSON as a double if possible.

This requires a JSON scalar of suitable type.

Returns: the JSON value as a double

Reimplemented from Field_blob.

◆ val_str()

String * Field_json::val_str	(	String *	buf1,
		String *	buf2
	)		const

finalvirtual

Retrieve the JSON value stored in this field as text.

Parameters

[in,out]	buf1	string buffer for converting JSON value to string
[in,out]	buf2	unused

Reimplemented from Field_blob.

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

sql/field.h
sql/field.cc

Public Member Functions

Private Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ Field_json() [1/2]

◆ Field_json() [2/2]

Member Function Documentation

◆ cast_to_int_type()

◆ charset()

◆ clone()

◆ cmp_binary()

◆ get_binary()

◆ get_date()

◆ get_diff_vector_and_length()

◆ get_time()

◆ has_charset()

◆ is_before_image_equal_to_after_image()

◆ is_equal()

◆ make_hash_key()

◆ make_sort_key() [1/3]

◆ make_sort_key() [2/3]

◆ make_sort_key() [3/3]

◆ pack_diff()

◆ sort_charset()

◆ sql_type()

◆ store() [1/4]

◆ store() [2/4]

◆ store() [3/4]

◆ store() [4/4]

◆ store_binary()

◆ store_decimal()

◆ store_json()

◆ store_time()

◆ type()

◆ unpack_diff()

◆ unsupported_conversion()

◆ val_decimal()

◆ val_int()

◆ val_json()

◆ val_real()

◆ val_str()