Field_datetime Class Reference

Inheritance diagram for Field_datetime:

List of all members.

Public Member Functions
	Field_datetime (uchar *ptr_arg, uchar *null_ptr_arg, uchar null_bit_arg, enum utype unireg_check_arg, const char *field_name_arg)
	Field_datetime (bool maybe_null_arg, const char *field_name_arg)
enum_field_types	type () const
type_conversion_status	store (longlong nr, bool unsigned_val)
type_conversion_status	store_packed (longlong nr)
type_conversion_status	reset (void)
longlong	val_int (void)
String *	val_str (String *, String *)
int	cmp (const uchar *, const uchar *)
void	make_sort_key (uchar *buff, uint length)
uint32	pack_length () const
void	sql_type (String &str) const
bool	zero_pack () const
bool	get_date (MYSQL_TIME *ltime, uint fuzzydate)
Field_datetime *	clone (MEM_ROOT *mem_root) const
Field_datetime *	clone () const
uchar *	pack (uchar *to, const uchar *from, uint max_length __attribute__((unused)), bool low_byte_first)
const uchar *	unpack (uchar *to, const uchar *from, uint param_data __attribute__((unused)), bool low_byte_first)
Static Public Attributes
static const int	PACK_LENGTH = 8
Protected Member Functions
type_conversion_status	store_internal (const MYSQL_TIME *ltime, int *error)
bool	get_date_internal (MYSQL_TIME *ltime)
ulonglong	date_flags (const THD *thd)
void	store_timestamp_internal (const struct timeval *tm)

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Constructor & Destructor Documentation

Field_datetime::Field_datetime	(	uchar *	ptr_arg,
		uchar *	null_ptr_arg,
		uchar	null_bit_arg,
		enum utype	unireg_check_arg,
		const char *	field_name_arg
	)		[inline]

DATETIME columns can be defined as having CURRENT_TIMESTAMP as the default value on inserts or updates. This constructor accepts a unireg_check value to initialize the column default expressions.

The implementation of function defaults is heavily entangled with the binary .frm file format. The utype enum is part of the file format specification but is declared a member of the Field class.

Four distinct unireg_check values are used for DATETIME columns to distinguish various cases of DEFAULT or ON UPDATE values. These values are:

• TIMESTAMP_DN_FIELD - means DATETIME DEFAULT CURRENT_TIMESTAMP.

• TIMESTAMP_UN_FIELD - means DATETIME DEFAULT <default value>=""> ON UPDATE CURRENT_TIMESTAMP, where <default value>=""> is an implicit or explicit expression other than CURRENT_TIMESTAMP or any synonym thereof (e.g. NOW().)

• TIMESTAMP_DNUN_FIELD - means DATETIME DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP.

• NONE - means that the column has neither DEFAULT CURRENT_TIMESTAMP, nor ON UPDATE CURRENT_TIMESTAMP

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Member Function Documentation

Field_datetime* Field_datetime::clone

(

MEM_ROOT *

mem_root

)

const [inline, virtual]

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.

Field_datetime* Field_datetime::clone

(

)

const [inline, virtual]

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.

Return values:

NULL	If memory allocation failed.

Implements Field.

ulonglong Field_datetime::date_flags

(

const THD *

thd

)

[protected, virtual]

Flags that are passed as "flag" argument to check_date(), number_to_datetime(), str_to_datetime().

Flags depend on the session sql_mode settings, such as MODE_NO_ZERO_DATE, MODE_NO_ZERO_IN_DATE. Also, Field_newdate, Field_datetime, Field_datetimef add TIME_FUZZY_DATE to the session sql_mode settings, to allow relaxed date format, while Field_timestamp, Field_timestampf do not.

Parameters:

thd

THD

Return values:

sql_mode

flags mixed with the field type flags.

Reimplemented from Field_temporal.

bool Field_datetime::get_date_internal

(

MYSQL_TIME *

ltime

)

[protected, virtual]

Low level function to get value into MYSQL_TIME, without checking for being valid.

Implements Field_temporal_with_date.

void Field_datetime::make_sort_key	(	uchar *	buff,
		uint	length
	)		[virtual]

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.

Implements Field.

type_conversion_status Field_datetime::store_internal	(	const MYSQL_TIME *	ltime,
		int *	error
	)		[protected, virtual]

Low level routine to store a MYSQL_TIME value into a field. The value must be already properly rounded or truncated and checked for being a valid TIME/DATE/DATETIME value.

Parameters:

IN	ltime MYSQL_TIME value.
OUT	error Error flag vector, set in case of error.

Return values:

false	In case of success.
true	In case of error.

Implements Field_temporal.

type_conversion_status Field_datetime::store_packed

(

longlong

nr

)

[virtual]

Store a temporal value in packed longlong format into a field. The packed value is compatible with TIME_to_longlong_time_packed(), TIME_to_longlong_date_packed() or TIME_to_longlong_datetime_packed(). Note, the value must be properly rounded or truncated according according to field->decimals().

Parameters:

nr	temporal value in packed longlong format.

Return values:

false	on success
true	on error

Reimplemented from Field.

void Field_datetime::store_timestamp_internal

(

const struct timeval *

tm

)

[protected, virtual]

Store "struct timeval" value into field. The value must be properly rounded or truncated according to the number of fractional second digits.

Implements Field_temporal_with_date_and_time.

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

• field.h
• field.cc