#include <field.h>

Inheritance diagram for Field_string:

Public Member Functions
	Field_string (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 cs)

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

enum_field_types	type () const final

bool	match_collation_to_optimize_range () const final

enum ha_base_keytype	key_type () const final

bool	zero_pack () const final

type_conversion_status	reset () final

type_conversion_status	store (const char to, size_t length, const CHARSET_INFO charset) final

type_conversion_status	store (longlong nr, bool unsigned_val) final

double	val_real () const final

longlong	val_int () const final

String *	val_str (String , String ) const final

LEX_CSTRING	val_str_quick () const
	Get the C-string value, without using String class. More...

my_decimal *	val_decimal (my_decimal *) const final

int	cmp (const uchar , const uchar ) const final

size_t	make_sort_key (uchar *buff, size_t length) const final
	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...

void	sql_type (String &str) const final

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...

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

uint	pack_length_from_metadata (uint field_metadata) const final

bool	compatible_field_size (uint field_metadata, Relay_log_info rli, uint16 mflags, int order_var) const final
	Check to see if field size is compatible with destination. More...

uint	row_pack_length () const final

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...

enum_field_types	real_type () const final

bool	has_charset () const final

Field_string *	clone (MEM_ROOT *mem_root) const final
	Makes a shallow copy of the Field object. More...

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

bool	is_text_key_type () const final

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)

type_conversion_status	store_decimal (const my_decimal *d) override
	Decimal representation of Field_str. More...

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

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...

type_conversion_status	store (double nr) override
	Store double value in Field_string or Field_varstring. More...

uint	repertoire () const final

const CHARSET_INFO *	charset () const override

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

uint32	max_display_length () const override

bool	str_needs_quotes () const final

uint	is_equal (const Create_field *new_field) const override
	Whether a field being created is type-compatible with an existing one. More...

void	add_to_cost (CostOfItem *cost) const override
	Update '*cost' with the fact that this Field is accessed. More...

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...

virtual type_conversion_status	store_time (MYSQL_TIME *ltime, uint8 dec_arg)
	Store MYSQL_TIME value with the given amount of decimal digits 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

virtual Item_result	cast_to_int_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 () const

virtual uint32	pack_length_in_rec () const

int	save_field_metadata (uchar *first_byte)

virtual uint32	data_length (ptrdiff_t row_offset=0) const

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 uint32	key_length () const

virtual enum_field_types	binlog_type () const

int	cmp (const uchar *str) const

virtual int	cmp_max (const uchar a, const uchar b, uint max_len) const

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

virtual int	cmp_offset (ptrdiff_t row_offset) const

virtual int	cmp_binary_offset (ptrdiff_t row_offset) const

virtual int	key_cmp (const uchar a, const uchar b) const

virtual int	key_cmp (const uchar *str, uint length) 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 void	mem_free ()

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 )

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

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)

virtual uchar *	pack_with_metadata_bytes (uchar to, const uchar from, uint max_length) const
	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...

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

uint	offset (uchar *record) const

void	copy_data (ptrdiff_t src_record_offset)

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

virtual bool	get_time (MYSQL_TIME *ltime) const

const CHARSET_INFO *	charset_for_protocol () const

virtual const CHARSET_INFO *	sort_charset () 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 uint32	char_length () const

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...

virtual const uchar *	data_ptr () const
	Return a const pointer to the actual data in the record buffer. 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
int	do_save_field_metadata (uchar *first_byte) const final
	Save the field metadata for string fields. 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_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 from_cs, const CHARSET_INFO to_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

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 = ' '

Constructor & Destructor Documentation

◆ Field_string() [1/2]

Field_string::Field_string	(	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 *	cs
	)

inline

◆ Field_string() [2/2]

Field_string::Field_string	(	uint32	len_arg,
		bool	is_nullable_arg,
		const char *	field_name_arg,
		const CHARSET_INFO *	cs
	)

inline

Member Function Documentation

◆ clone()

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

inlinefinalvirtual

Makes a shallow copy of the Field object.

Note: This member function must be overridden in all concrete subclasses. Several of the Field subclasses are concrete even though they are not leaf classes, so the compiler will not always catch this.

Parameters

mem_root MEM_ROOT to use for memory allocation.

Return values

NULL	If memory allocation failed.

Implements Field.

◆ cmp()

int Field_string::cmp	(	const uchar *	a_ptr,
		const uchar *	b_ptr
	)		const

finalvirtual

Implements Field.

◆ compatible_field_size()

bool Field_string::compatible_field_size	(	uint	field_metadata,
		Relay_log_info *	,
		uint16	,
		int *	order_var
	)		const

finalvirtual

Check to see if field size is compatible with destination.

This method is used in row-based replication to verify that the slave's field size is less than or equal to the master's field size. The encoded field metadata (from the master or source) is decoded and compared to the size of this field (the slave or destination).

The comparison is made so that if the source data (from the master) is less than the target data (on the slave), -1 is returned in *order_var. This implies that a conversion is necessary, but that it is lossy and can result in truncation of the value.

If the source data is strictly greater than the target data, 1 is returned in *order_var. This implies that the source type can is contained in the target type and that a conversion is necessary but is non-lossy.

If no conversion is required to fit the source type in the target type, 0 is returned in *order_var.

Parameters

field_metadata	Encoded size in field metadata
order_var	Pointer to variable where the order between the source field and this field will be returned.

Returns: true if this field's size is compatible with the master's field size, false otherwise.

Reimplemented from Field.

◆ do_save_field_metadata()

int Field_string::do_save_field_metadata ( uchar * metadata_ptr ) const

finalprivatevirtual

Save the field metadata for string fields.

Saves the real type in the first byte and the field length in the second byte of the field metadata array at index of *metadata_ptr and (metadata_ptr + 1).

Note: In order to be able to handle lengths exceeding 255 and be backwards-compatible with pre-5.1.26 servers, an extra two bits of the length has been added to the metadata in such a way that if they are set, a new unrecognized type is generated. This will cause pre-5.1-26 servers to stop due to a field type mismatch, while new servers will be able to extract the extra bits. If the length is <256, there will be no difference and both a new and an old server will be able to handle it.; The extra two bits are added to bits 13 and 14 of the parameter data (with 1 being the least siginficant bit and 16 the most significant bit of the word) by xoring the extra length bits with the real type. Since all allowable types have 0xF as most significant bits of the metadata word, lengths <256 will not affect the real type at all, while all other values will result in a non-existent type in the range 17-244.

See also: Field_string::unpack

Parameters

metadata_ptr First byte of field metadata

Returns: number of bytes written to metadata_ptr

Reimplemented from Field.

◆ get_key_image()

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

finalvirtual

Reimplemented from Field.

◆ has_charset()

bool Field_string::has_charset ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ is_text_key_type()

bool Field_string::is_text_key_type ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ key_type()

enum ha_base_keytype Field_string::key_type ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ make_sort_key() [1/2]

size_t Field_string::make_sort_key	(	uchar *	buff,
		size_t	length
	)		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.

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.

Implements Field.

◆ make_sort_key() [2/2]

size_t Field_string::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.

◆ match_collation_to_optimize_range()

bool Field_string::match_collation_to_optimize_range ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ max_packed_col_length()

uint Field_string::max_packed_col_length ( ) const

finalvirtual

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

Returns: maximum size of a row when stored in the filesort buffer.

Reimplemented from Field.

◆ pack()

uchar * Field_string::pack	(	uchar *	to,
		const uchar *	from,
		size_t	max_length
	)		const

finalvirtual

Pack the field into a format suitable for storage and transfer.

To implement packing functionality, only the virtual function should be overridden. The other functions are just convenience functions and hence should not be overridden.

The actual format is opaque and will vary between types of Field (it is meant to be unpacked by unpack(), but be aware that it is used among others in the replication log, so you cannot change it without incurring a format break.

Note: The default implementation just copies the raw bytes of the record into the destination, but never more than max_length characters.

Parameters

to	Pointer to memory area where representation of field should be put.
from	Pointer to memory area where record representation of field is stored, typically field->field_ptr().
max_length	Available space in “to”, in bytes. pack() will not write more bytes than this; if the field is too short, the contents are not unpackable by unpack(). (It is nominally supposed to be a prefix of what would have been written with a full buffer, ie., the same as packing and then truncating the output, but not all Field classes follow this.)

Returns: The byte after the last byte in “to” written to. If the return value is equal to (to + max_length), it could either be that the value fit exactly, or that the buffer was too small; you cannot distinguish between the two cases based on the return value alone.

Reimplemented from Field.

◆ pack_length_from_metadata()

uint Field_string::pack_length_from_metadata ( uint field_metadata ) const

inlinefinalvirtual

Reimplemented from Field.

◆ real_type()

enum_field_types Field_string::real_type ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ reset()

type_conversion_status Field_string::reset ( )

inlinefinalvirtual

Reimplemented from Field.

◆ row_pack_length()

uint Field_string::row_pack_length ( ) const

inlinefinalvirtual

Reimplemented from Field.

◆ sql_type()

void Field_string::sql_type ( String & str ) const

finalvirtual

Implements Field.

◆ store() [1/2]

type_conversion_status Field_string::store	(	const char *	to,
		size_t	length,
		const CHARSET_INFO *	charset
	)

finalvirtual

Implements Field_str.

◆ store() [2/2]

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

finalvirtual

Implements Field_str.

◆ type()

enum_field_types Field_string::type ( ) const

inlinefinalvirtual

Implements Field.

◆ unpack()

const uchar * Field_string::unpack	(	uchar *	to,
		const uchar *	from,
		uint	param_data
	)

finalvirtual

Unpack a string field from row data.

This method is used to unpack a string field from a master whose size of the field is less than that of the slave. Note that there can be a variety of field types represented with this class. Certain types like ENUM or SET are processed differently. Hence, the upper byte of the param_data argument contains the result of field->real_type() from the master.

Note: For information about how the length is packed, see Field_string::do_save_field_metadata

Parameters

to	Destination of the data
from	Source of the data
param_data	Real type (upper) and length (lower) values

Returns: New pointer into memory based on from + length of the data

Reimplemented from Field.

◆ val_decimal()

my_decimal * Field_string::val_decimal ( my_decimal * decimal_value ) const

finalvirtual

Implements Field.

◆ val_int()

longlong Field_string::val_int ( void ) const

finalvirtual

Implements Field.

◆ val_real()

double Field_string::val_real ( void ) const

finalvirtual

Implements Field.

◆ val_str()

String * Field_string::val_str	(	String *	,
		String *	val_ptr
	)		const

finalvirtual

Implements Field.

◆ val_str_quick()

LEX_CSTRING Field_string::val_str_quick ( ) const

inline

Get the C-string value, without using String class.

Returns: The C-string value of this field.

◆ zero_pack()

bool Field_string::zero_pack ( ) const

inlinefinalvirtual

Reimplemented from Field.

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

Constructor & Destructor Documentation

◆ Field_string() [1/2]

◆ Field_string() [2/2]

Member Function Documentation

◆ clone()

◆ cmp()

◆ compatible_field_size()

◆ do_save_field_metadata()

◆ get_key_image()

◆ has_charset()

◆ is_text_key_type()

◆ key_type()

◆ make_sort_key() [1/2]

◆ make_sort_key() [2/2]

◆ match_collation_to_optimize_range()

◆ max_packed_col_length()

◆ pack()

◆ pack_length_from_metadata()

◆ real_type()

◆ reset()

◆ row_pack_length()

◆ sql_type()

◆ store() [1/2]

◆ store() [2/2]

◆ type()

◆ unpack()

◆ val_decimal()

◆ val_int()

◆ val_real()

◆ val_str()

◆ val_str_quick()

◆ zero_pack()