types

package
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 Go to latest Published: Nov 24, 2016 License: Apache-2.0 Imports: 16 Imported by: 0

Documentation

Index

Constants

View Source 
const (
	MinBitWidth = 1
	MaxBitWidth = 64
	// UnspecifiedBitWidth is the unspecified with if you want to calculate bit width dynamically.
	UnspecifiedBitWidth = -1
)

Min and Max bit width.

View Source 
const (
	KindNull  byte = 0
	KindInt64 byte = iota + 1
	KindUint64
	KindFloat32
	KindFloat64
	KindString
	KindBytes
	KindMysqlBit
	KindMysqlDecimal
	KindMysqlDuration
	KindMysqlEnum
	KindMysqlHex
	KindMysqlSet
	KindMysqlTime
	KindRow
	KindInterface
	KindMinNotNull
	KindMaxValue
)

Kind constants.

View Source 
const (
	// UnspecifiedFsp is the unspecified fractional seconds part.
	UnspecifiedFsp int = -1
	// MaxFsp is the maximum digit of fractional seconds part.
	MaxFsp int = 6
	// MinFsp is the minimum digit of fractional seconds part.
	MinFsp int = 0
	// DefaultFsp is the default digit of fractional seconds part.
	// MySQL use 0 as the default Fsp.
	DefaultFsp int = 0
)
View Source 
const (
	MaxFraction = 30
	DivFracIncr = 4
)

constant values.

View Source 
const (
	DateFormat = "2006-01-02"
	TimeFormat = "2006-01-02 15:04:05"
	// TimeFSPFormat is time format with fractional seconds precision.
	TimeFSPFormat = "2006-01-02 15:04:05.000000"
)

Time format without fractional seconds precision.

View Source 
const (
	// MinYear is the minimum for mysql year type.
	MinYear int16 = 1901
	// MaxYear is the maximum for mysql year type.
	MaxYear int16 = 2155

	// MinTime is the minimum for mysql time type.
	MinTime = -time.Duration(838*3600+59*60+59) * time.Second
	// MaxTime is the maximum for mysql time type.
	MaxTime = time.Duration(838*3600+59*60+59) * time.Second
)
View Source 
const (
	UnspecifiedLength int = -1
)

UnspecifiedLength is unspecified length.

Variables

View Source 
var (
	// ErrDataTooLong is returned when converts a string value that is longer than field type length.
	ErrDataTooLong = terror.ClassTypes.New(codeDataTooLong, "Data Too Long")
	// ErrTruncated is returned when data has been truncated during convertion.
	ErrTruncated = terror.ClassTypes.New(codeTruncated, "Data Truncated")
	// ErrOverflow is returned when data is out of range for a field type.
	ErrOverflow = terror.ClassTypes.New(codeOverflow, "Data Out Of Range")
	// ErrDivByZero is return when do division by 0.
	ErrDivByZero = terror.ClassTypes.New(codeDivByZero, "Division by 0")
	// ErrBadNumber is return when parsing an invalid binary decimal number.
	ErrBadNumber = terror.ClassTypes.New(codeBadNumber, "Bad Number")
)
View Source 
var (
	ErrInvalidTimeFormat = errors.New("invalid time format")
	ErrInvalidYearFormat = errors.New("invalid year format")
	ErrInvalidYear       = errors.New("invalid year")
)

Portable analogs of some common call errors.

View Source 
var (
	// ZeroDuration is the zero value for Duration type.
	ZeroDuration = Duration{Duration: time.Duration(0), Fsp: DefaultFsp}

	// ZeroTime is the zero value for time.Time type.
	ZeroTime = time.Date(0, 0, 0, 0, 0, 0, 0, time.Local)

	// ZeroDatetime is the zero value for datetime Time.
	ZeroDatetime = Time{
		Time: ZeroTime,
		Type: mysql.TypeDatetime,
		Fsp:  DefaultFsp,
	}

	// ZeroTimestamp is the zero value for timestamp Time.
	ZeroTimestamp = Time{
		Time: ZeroTime,
		Type: mysql.TypeTimestamp,
		Fsp:  DefaultFsp,
	}

	// ZeroDate is the zero value for date Time.
	ZeroDate = Time{
		Time: ZeroTime,
		Type: mysql.TypeDate,
		Fsp:  DefaultFsp,
	}
)

Zero values for different types.

View Source 
var (
	// MinDatetime is the minimum for mysql datetime type.
	MinDatetime = time.Date(1000, 1, 1, 0, 0, 0, 0, time.Local)
	// MaxDatetime is the maximum for mysql datetime type.
	MaxDatetime = time.Date(9999, 12, 31, 23, 59, 59, 999999, time.Local)

	// MinTimestamp is the minimum for mysql timestamp type.
	MinTimestamp = time.Date(1970, 1, 1, 0, 0, 1, 0, time.UTC)
	// MaxTimestamp is the maximum for mysql timestamp type.
	MaxTimestamp = time.Date(2038, 1, 19, 3, 14, 7, 999999, time.UTC)

	// WeekdayNames lists names of weekdays, which are used in builtin time function `dayname`.
	WeekdayNames = []string{
		"Monday",
		"Tuesday",
		"Wednesday",
		"Thursday",
		"Friday",
		"Saturday",
		"Sunday",
	}

	// MonthNames lists names of months, which are used in builtin time function `monthname`.
	MonthNames = []string{
		"January", "February",
		"March", "April",
		"May", "June",
		"July", "August",
		"September", "October",
		"November", "December",
	}
)
View Source 
var ErrArithOverflow = errors.New("operation overflow")

ErrArithOverflow is the error for arthimetic operation overflow.

View Source 
var (
	// ErrValueTruncated is used when a value has been truncated during conversion.
	ErrValueTruncated = errors.New("value has been truncated")
)

Functions

func AddInt64 

func AddInt64(a int64, b int64) (int64, error)

AddInt64 adds int64 a and b if no overflow, otherwise returns error.

func AddInteger 

func AddInteger(a uint64, b int64) (uint64, error)

AddInteger adds uint64 a and int64 b and returns uint64 if no overflow error.

func AddUint64 

func AddUint64(a uint64, b uint64) (uint64, error)

AddUint64 adds uint64 a and b if no overflow, else returns error.

func AdjustYear 

func AdjustYear(y int64) (int64, error)

AdjustYear is used for adjusting year and checking its validation.

func Compare 

func Compare(a, b interface{}) (int, error)

Compare returns an integer comparing the interface a with b. a > b -> 1 a = b -> 0 a < b -> -1

func CompareFloat64 

func CompareFloat64(x, y float64) int

CompareFloat64 returns an integer comparing the float64 x to y.

func CompareInt64 

func CompareInt64(x, y int64) int

CompareInt64 returns an integer comparing the int64 x to y.

func CompareString 

func CompareString(x, y string) int

CompareString returns an integer comparing the string x to y.

func CompareUint64 

func CompareUint64(x, y uint64) int

CompareUint64 returns an integer comparing the uint64 x to y.

func Convert 

func Convert(val interface{}, target *FieldType) (v interface{}, err error)

Convert converts the val with type tp.

func DatumsToInterfaces 

func DatumsToInterfaces(datums []Datum) []interface{}

DatumsToInterfaces converts a datum slice to interface slice.

func DecimalAdd 

func DecimalAdd(from1, from2, to *MyDecimal) error

DecimalAdd adds two decimals, sets the result to 'to'.

func DecimalDiv 

func DecimalDiv(from1, from2, to *MyDecimal, fracIncr int) error

DecimalDiv does division of two decimals.

from1 - dividend from2 - divisor to - quotient fracIncr - increment of fraction

func DecimalMod 

func DecimalMod(from1, from2, to *MyDecimal) error

DecimalMod does modulus of two decimals. 

    from1   - dividend
    from2   - divisor
    to      - modulus

RETURN VALUE
  E_DEC_OK/E_DEC_TRUNCATED/E_DEC_OVERFLOW/E_DEC_DIV_ZERO;

NOTES
  see do_div_mod()

DESCRIPTION
  the modulus R in    R = M mod N

 is defined as

   0 <= |R| < |M|
   sign R == sign M
   R = M - k*N, where k is integer

 thus, there's no requirement for M or N to be integers

func DecimalMul 

func DecimalMul(from1, from2, to *MyDecimal) error

DecimalMul multiplies two decimals. 

    from1, from2 - factors
    to      - product

RETURN VALUE
  E_DEC_OK/E_DEC_TRUNCATED/E_DEC_OVERFLOW;

NOTES
  in this implementation, with wordSize=4 we have digitsPerWord=9,
  and 63-digit number will take only 7 words (basically a 7-digit
  "base 999999999" number).  Thus there's no need in fast multiplication
  algorithms, 7-digit numbers can be multiplied with a naive O(n*n)
  method.

  XXX if this library is to be used with huge numbers of thousands of
  digits, fast multiplication must be implemented.

func DecimalPeak 

func DecimalPeak(b []byte) (int, error)

DecimalPeak returns the length of the encoded decimal.

func DecimalSub 

func DecimalSub(from1, from2, to *MyDecimal) error

DecimalSub subs one decimal from another, sets the result to 'to'.

func DefaultCharsetForType 

func DefaultCharsetForType(tp byte) (string, string)

DefaultCharsetForType returns the default charset/collation for mysql type.

func DefaultTypeForValue 

func DefaultTypeForValue(value interface{}, tp *FieldType)

DefaultTypeForValue returns the default FieldType for the value.

func DivInt64 

func DivInt64(a int64, b int64) (int64, error)

DivInt64 divides int64 a with b, returns int64 if no overflow error. It just checks overflow, if b is zero, a "divide by zero" panic throws.

func DivIntWithUint 

func DivIntWithUint(a int64, b uint64) (uint64, error)

DivIntWithUint divides int64 a with uint64 b, returns uint64 if no overflow error. It just checks overflow, if b is zero, a "divide by zero" panic throws.

func DivUintWithInt 

func DivUintWithInt(a uint64, b int64) (uint64, error)

DivUintWithInt divides uint64 a with int64 b, returns uint64 if no overflow error. It just checks overflow, if b is zero, a "divide by zero" panic throws.

func EOFAsNil 

func EOFAsNil(err error) error

EOFAsNil filtrates errors, If err is equal to io.EOF returns nil.

func EqualDatums 

func EqualDatums(a []Datum, b []Datum) (bool, error)

EqualDatums compare if a and b contains the same datum values.

func ExtractTimeNum 

func ExtractTimeNum(unit string, t Time) (int64, error)

ExtractTimeNum extracts time value number from time unit and format.

func ExtractTimeValue 

func ExtractTimeValue(unit string, format string) (int64, int64, int64, time.Duration, error)

ExtractTimeValue extracts time value from time unit and format.

func InvOp2 

func InvOp2(x, y interface{}, o opcode.Op) (interface{}, error)

InvOp2 returns an invalid operation error.

func IsClockUnit 

func IsClockUnit(unit string) bool

IsClockUnit returns true when unit is interval unit with hour, minute or second.

func IsDateFormat 

func IsDateFormat(format string) bool

IsDateFormat returns true when the specified time format could contain only date.

func IsTypeBlob 

func IsTypeBlob(tp byte) bool

IsTypeBlob returns a boolean indicating whether the tp is a blob type.

func IsTypeChar 

func IsTypeChar(tp byte) bool

IsTypeChar returns a boolean indicating whether the tp is the char type like a string type or a varchar type.

func MergeFieldType 

func MergeFieldType(a byte, b byte) byte

MergeFieldType merges two MySQL type to a new type. This is used in hybrid field type expression. For example "select case c when 1 then 2 when 2 then 'tidb' from t;" The result field type of the case expression is the merged type of the two when clause. See https://github.com/mysql/mysql-server/blob/5.7/sql/field.cc#L1042

func MulInt64 

func MulInt64(a int64, b int64) (int64, error)

MulInt64 multiplies int64 a and b and returns int64 if no overflow error.

func MulInteger 

func MulInteger(a uint64, b int64) (uint64, error)

MulInteger multiplies uint64 a and int64 b, and returns uint64 if no overflow error.

func MulUint64 

func MulUint64(a uint64, b uint64) (uint64, error)

MulUint64 multiplies uint64 a and b and returns uint64 if no overflow error.

func ParseHexStr 

func ParseHexStr(s string) (string, error)

ParseHexStr parses hexadecimal literal as string. See https://dev.mysql.com/doc/refman/5.7/en/hexadecimal-literals.html

func ParseYear 

func ParseYear(str string) (int16, error)

ParseYear parses a formatted string and returns a year number.

func Round 

func Round(f float64, dec int) float64

Round rounds the argument f to dec decimal places. dec defaults to 0 if not specified. dec can be negative to cause dec digits left of the decimal point of the value f to become zero.

func RoundFloat 

func RoundFloat(f float64) float64

RoundFloat rounds float val to the nearest integer value with float64 format, like MySQL Round function. RoundFloat uses default rounding mode, see https://dev.mysql.com/doc/refman/5.7/en/precision-math-rounding.html so rounding use "round half away from zero". e.g, 1.5 -> 2, -1.5 -> -2.

func SortDatums 

func SortDatums(datums []Datum) error

SortDatums sorts a slice of datum.

func StrToFloat 

func StrToFloat(str string) (float64, error)

StrToFloat converts a string to a float64 in best effort.

func StrToInt 

func StrToInt(str string) (int64, error)

StrToInt converts a string to an integer in best effort. TODO: handle overflow and add unittest.

func SubInt64 

func SubInt64(a int64, b int64) (int64, error)

SubInt64 subtracts int64 a with b and returns int64 if no overflow error.

func SubIntWithUint 

func SubIntWithUint(a int64, b uint64) (uint64, error)

SubIntWithUint subtracts int64 a with uint64 b and returns uint64 if no overflow error.

func SubUint64 

func SubUint64(a uint64, b uint64) (uint64, error)

SubUint64 subtracts uint64 a with b and returns uint64 if no overflow error.

func SubUintWithInt 

func SubUintWithInt(a uint64, b int64) (uint64, error)

SubUintWithInt subtracts uint64 a with int64 b and returns uint64 if no overflow error.

func ToString 

func ToString(value interface{}) (string, error)

ToString converts an interface to a string.

func TruncateFloat 

func TruncateFloat(f float64, flen int, decimal int) (float64, error)

TruncateFloat tries to truncate f. If the result exceeds the max/min float that flen/decimal allowed, returns the max/min float allowed.

func TypeStr 

func TypeStr(tp byte) (r string)

TypeStr converts tp to a string.

func TypeToStr 

func TypeToStr(tp byte, cs string) (r string)

TypeToStr converts a field to a string. It is used for converting Text to Blob, or converting Char to Binary. Args: 

tp: type enum
cs: charset

Types

type Bit 

type Bit struct {
	// Value holds the value for bit type.
	Value uint64

	// Width is the display with for bit value.
	// e.g, with is 8, 0 is for 0b00000000.
	Width int
}

Bit is for mysql bit type.

func ParseBit 

func ParseBit(s string, width int) (Bit, error)

ParseBit parses bit string. The string format can be b'val', B'val' or 0bval, val must be 0 or 1. Width is the display width for bit representation. -1 means calculating width dynamically, using following algorithm: (len("011101") + 7) & ^7, e.g, if bit string is 0b01, the above will return 8 for its bit width.

func (Bit) String 

func (b Bit) String() string

String implements fmt.Stringer interface.

func (Bit) ToNumber 

func (b Bit) ToNumber() float64

ToNumber changes bit type to float64 for numeric operation. MySQL treats bit as double type.

func (Bit) ToString 

func (b Bit) ToString() string

ToString returns the binary string for bit type.

type Datum 

type Datum struct {
	// contains filtered or unexported fields
}

Datum is a data box holds different kind of data. It has better performance and is easier to use than `interface{}`.

func CalculateSum 

func CalculateSum(sum Datum, v Datum) (Datum, error)

CalculateSum adds v to sum.

func CoerceArithmetic 

func CoerceArithmetic(a Datum) (d Datum, err error)

CoerceArithmetic converts datum to appropriate datum for arithmetic computing.

func CoerceDatum 

func CoerceDatum(a, b Datum) (x, y Datum, err error)

CoerceDatum changes type. If a or b is Float, changes the both to Float. Else if a or b is Decimal, changes the both to Decimal. Else if a or b is Uint and op is not div, mod, or intDiv changes the both to Uint.

func ComputeBitAnd 

func ComputeBitAnd(a, b Datum) (d Datum, err error)

ComputeBitAnd computes the result of a & b.

func ComputeBitNeg 

func ComputeBitNeg(a Datum) (d Datum, err error)

ComputeBitNeg computes the result of ~a.

func ComputeBitOr 

func ComputeBitOr(a, b Datum) (d Datum, err error)

ComputeBitOr computes the result of a | b.

func ComputeBitXor 

func ComputeBitXor(a, b Datum) (d Datum, err error)

ComputeBitXor computes the result of a ^ b.

func ComputeDiv 

func ComputeDiv(a, b Datum) (d Datum, err error)

ComputeDiv computes the result of a/b.

func ComputeIntDiv 

func ComputeIntDiv(a, b Datum) (d Datum, err error)

ComputeIntDiv computes the result of a / b, both a and b are integer.

func ComputeLeftShift 

func ComputeLeftShift(a, b Datum) (d Datum, err error)

ComputeLeftShift computes the result of a >> b.

func ComputeMinus 

func ComputeMinus(a, b Datum) (d Datum, err error)

ComputeMinus computes the result of a-b.

func ComputeMod 

func ComputeMod(a, b Datum) (d Datum, err error)

ComputeMod computes the result of a mod b.

func ComputeMul 

func ComputeMul(a, b Datum) (d Datum, err error)

ComputeMul computes the result of a*b.

func ComputePlus 

func ComputePlus(a, b Datum) (d Datum, err error)

ComputePlus computes the result of a+b.

func ComputeRightShift 

func ComputeRightShift(a, b Datum) (d Datum, err error)

ComputeRightShift computes the result of a << b.

func MakeDatums 

func MakeDatums(args ...interface{}) []Datum

MakeDatums creates datum slice from interfaces.

func MaxValueDatum 

func MaxValueDatum() Datum

MaxValueDatum returns a datum represents max value.

func MinNotNullDatum 

func MinNotNullDatum() Datum

MinNotNullDatum returns a datum represents minimum not null value.

func NewBytesDatum 

func NewBytesDatum(b []byte) (d Datum)

NewBytesDatum creates a new Datum from a byte slice.

func NewDatum 

func NewDatum(in interface{}) (d Datum)

NewDatum creates a new Datum from an interface{}.

func NewDecimalDatum 

func NewDecimalDatum(dec *MyDecimal) (d Datum)

NewDecimalDatum creates a new Datum form a MyDecimal value.

func NewDurationDatum 

func NewDurationDatum(dur Duration) (d Datum)

NewDurationDatum creates a new Datum from a Duration value.

func NewFloat32Datum 

func NewFloat32Datum(f float32) (d Datum)

NewFloat32Datum creates a new Datum from a float32 value.

func NewFloat64Datum 

func NewFloat64Datum(f float64) (d Datum)

NewFloat64Datum creates a new Datum from a float64 value.

func NewIntDatum 

func NewIntDatum(i int64) (d Datum)

NewIntDatum creates a new Datum from an int64 value.

func NewStringDatum 

func NewStringDatum(s string) (d Datum)

NewStringDatum creates a new Datum from a string.

func NewUintDatum 

func NewUintDatum(i uint64) (d Datum)

NewUintDatum creates a new Datum from an uint64 value.

func (*Datum) Cast 

func (d *Datum) Cast(target *FieldType) (ad Datum, err error)

Cast casts datum to certain types.

func (*Datum) Collation 

func (d *Datum) Collation() byte

Collation gets the collation of the datum.

func (*Datum) CompareDatum 

func (d *Datum) CompareDatum(ad Datum) (int, error)

CompareDatum compares datum to another datum. TODO: return error properly.

func (*Datum) ConvertTo 

func (d *Datum) ConvertTo(target *FieldType) (Datum, error)

ConvertTo converts a datum to the target field type.

func (*Datum) Frac 

func (d *Datum) Frac() int

Frac gets the frac of the datum.

func (*Datum) GetBytes 

func (d *Datum) GetBytes() []byte

GetBytes gets bytes value.

func (*Datum) GetFloat32 

func (d *Datum) GetFloat32() float32

GetFloat32 gets float32 value.

func (*Datum) GetFloat64 

func (d *Datum) GetFloat64() float64

GetFloat64 gets float64 value.

func (*Datum) GetInt64 

func (d *Datum) GetInt64() int64

GetInt64 gets int64 value.

func (*Datum) GetInterface 

func (d *Datum) GetInterface() interface{}

GetInterface gets interface value.

func (*Datum) GetMysqlBit 

func (d *Datum) GetMysqlBit() Bit

GetMysqlBit gets Bit value

func (*Datum) GetMysqlDecimal 

func (d *Datum) GetMysqlDecimal() *MyDecimal

GetMysqlDecimal gets Decimal value

func (*Datum) GetMysqlDuration 

func (d *Datum) GetMysqlDuration() Duration

GetMysqlDuration gets Duration value

func (*Datum) GetMysqlEnum 

func (d *Datum) GetMysqlEnum() Enum

GetMysqlEnum gets Enum value

func (*Datum) GetMysqlHex 

func (d *Datum) GetMysqlHex() Hex

GetMysqlHex gets Hex value

func (*Datum) GetMysqlSet 

func (d *Datum) GetMysqlSet() Set

GetMysqlSet gets Set value

func (*Datum) GetMysqlTime 

func (d *Datum) GetMysqlTime() Time

GetMysqlTime gets types.Time value

func (*Datum) GetRow 

func (d *Datum) GetRow() []Datum

GetRow gets row value.

func (*Datum) GetString 

func (d *Datum) GetString() string

GetString gets string value.

func (*Datum) GetUint64 

func (d *Datum) GetUint64() uint64

GetUint64 gets uint64 value.

func (*Datum) GetValue 

func (d *Datum) GetValue() interface{}

GetValue gets the value of the datum of any kind.

func (*Datum) IsNull 

func (d *Datum) IsNull() bool

IsNull checks if datum is null.

func (*Datum) Kind 

func (d *Datum) Kind() byte

Kind gets the kind of the datum.

func (*Datum) Length 

func (d *Datum) Length() int

Length gets the length of the datum.

func (*Datum) SetBytes 

func (d *Datum) SetBytes(b []byte)

SetBytes sets bytes value to datum.

func (*Datum) SetBytesAsString 

func (d *Datum) SetBytesAsString(b []byte)

SetBytesAsString sets bytes value to datum as string type.

func (*Datum) SetCollation 

func (d *Datum) SetCollation(collation byte)

SetCollation sets the collation of the datum.

func (*Datum) SetFloat32 

func (d *Datum) SetFloat32(f float32)

SetFloat32 sets float32 value.

func (*Datum) SetFloat64 

func (d *Datum) SetFloat64(f float64)

SetFloat64 sets float64 value.

func (*Datum) SetFrac 

func (d *Datum) SetFrac(frac int)

SetFrac sets the frac of the datum.

func (*Datum) SetInt64 

func (d *Datum) SetInt64(i int64)

SetInt64 sets int64 value.

func (*Datum) SetInterface 

func (d *Datum) SetInterface(x interface{})

SetInterface sets interface to datum.

func (*Datum) SetLength 

func (d *Datum) SetLength(l int)

SetLength sets the length of the datum

func (*Datum) SetMysqlBit 

func (d *Datum) SetMysqlBit(b Bit)

SetMysqlBit sets Bit value

func (*Datum) SetMysqlDecimal 

func (d *Datum) SetMysqlDecimal(b *MyDecimal)

SetMysqlDecimal sets Decimal value

func (*Datum) SetMysqlDuration 

func (d *Datum) SetMysqlDuration(b Duration)

SetMysqlDuration sets Duration value

func (*Datum) SetMysqlEnum 

func (d *Datum) SetMysqlEnum(b Enum)

SetMysqlEnum sets Enum value

func (*Datum) SetMysqlHex 

func (d *Datum) SetMysqlHex(b Hex)

SetMysqlHex sets Hex value

func (*Datum) SetMysqlSet 

func (d *Datum) SetMysqlSet(b Set)

SetMysqlSet sets Set value

func (*Datum) SetMysqlTime 

func (d *Datum) SetMysqlTime(b Time)

SetMysqlTime sets types.Time value

func (*Datum) SetNull 

func (d *Datum) SetNull()

SetNull sets datum to nil.

func (*Datum) SetRow 

func (d *Datum) SetRow(ds []Datum)

SetRow sets row value.

func (*Datum) SetString 

func (d *Datum) SetString(s string)

SetString sets string value.

func (*Datum) SetUint64 

func (d *Datum) SetUint64(i uint64)

SetUint64 sets uint64 value.

func (*Datum) SetValue 

func (d *Datum) SetValue(val interface{})

SetValue sets any kind of value.

func (*Datum) ToBool 

func (d *Datum) ToBool() (int64, error)

ToBool converts to a bool. We will use 1 for true, and 0 for false.

func (*Datum) ToDecimal 

func (d *Datum) ToDecimal() (*MyDecimal, error)

ToDecimal converts to a decimal.

func (*Datum) ToFloat64 

func (d *Datum) ToFloat64() (float64, error)

ToFloat64 converts to a float64

func (*Datum) ToInt64 

func (d *Datum) ToInt64() (int64, error)

ToInt64 converts to a int64.

func (*Datum) ToString 

func (d *Datum) ToString() (string, error)

ToString gets the string representation of the datum.

type Duration 

type Duration struct {
	time.Duration
	// Fsp is short for Fractional Seconds Precision.
	// See http://dev.mysql.com/doc/refman/5.7/en/fractional-seconds.html
	Fsp int
}

Duration is the type for MySQL time type.

func ParseDuration 

func ParseDuration(str string, fsp int) (Duration, error)

ParseDuration parses the time form a formatted string with a fractional seconds part, returns the duration type Time value. See http://dev.mysql.com/doc/refman/5.7/en/fractional-seconds.html

func (Duration) Compare 

func (d Duration) Compare(o Duration) int

Compare returns an integer comparing the Duration instant t to o. If d is after o, return 1, equal o, return 0, before o, return -1.

func (Duration) CompareString 

func (d Duration) CompareString(str string) (int, error)

CompareString is like Compare, but parses str to Duration then compares.

func (Duration) ConvertToTime 

func (d Duration) ConvertToTime(tp uint8) (Time, error)

ConvertToTime converts duration to Time. Tp is TypeDatetime, TypeTimestamp and TypeDate.

func (Duration) Hour 

func (d Duration) Hour() int

Hour returns current hour. e.g, hour("11:11:11") -> 11

func (Duration) MicroSecond 

func (d Duration) MicroSecond() int

MicroSecond returns current microsecond. e.g, hour("11:11:11.11") -> 110000

func (Duration) Minute 

func (d Duration) Minute() int

Minute returns current minute. e.g, hour("11:11:11") -> 11

func (Duration) RoundFrac 

func (d Duration) RoundFrac(fsp int) (Duration, error)

RoundFrac rounds fractional seconds precision with new fsp and returns a new one. We will use the “round half up” rule, e.g, >= 0.5 -> 1, < 0.5 -> 0, so 10:10:10.999999 round 0 -> 10:10:11 and 10:10:10.000000 round 0 -> 10:10:10

func (Duration) Second 

func (d Duration) Second() int

Second returns current second. e.g, hour("11:11:11") -> 11

func (Duration) String 

func (d Duration) String() string

String returns the time formatted using default TimeFormat and fsp.

func (Duration) ToNumber 

func (d Duration) ToNumber() *MyDecimal

ToNumber changes duration to number format. e.g, 10:10:10 -> 101010

type Enum 

type Enum struct {
	Name  string
	Value uint64
}

Enum is for MySQL enum type.

func ParseEnumName 

func ParseEnumName(elems []string, name string) (Enum, error)

ParseEnumName creates a Enum with item name.

func ParseEnumValue 

func ParseEnumValue(elems []string, number uint64) (Enum, error)

ParseEnumValue creates a Enum with special number.

func (Enum) String 

func (e Enum) String() string

String implements fmt.Stringer interface.

func (Enum) ToNumber 

func (e Enum) ToNumber() float64

ToNumber changes enum index to float64 for numeric operation.

type FieldType 

type FieldType struct {
	Tp      byte
	Flag    uint
	Flen    int
	Decimal int
	Charset string
	Collate string
	// Elems is the element list for enum and set type.
	Elems []string
}

FieldType records field type information.

func NewFieldType 

func NewFieldType(tp byte) *FieldType

NewFieldType returns a FieldType, with a type and other information about field type.

func (*FieldType) CompactStr 

func (ft *FieldType) CompactStr() string

CompactStr only considers Tp/CharsetBin/Flen/Deimal. This is used for showing column type in infoschema.

func (*FieldType) Init 

func (ft *FieldType) Init(tp byte)

Init initializes the FieldType data.

func (*FieldType) String 

func (ft *FieldType) String() string

String joins the information of FieldType and returns a string.

type Hex 

type Hex struct {
	// Value holds numeric value for hexadecimal literal.
	Value int64
}

Hex is for mysql hexadecimal literal type.

func ParseHex 

func ParseHex(s string) (Hex, error)

ParseHex parses hexadecimal literal string. The string format can be X'val', x'val' or 0xval. val must in (0...9, a...f, A...F).

func (Hex) String 

func (h Hex) String() string

String implements fmt.Stringer interface.

func (Hex) ToNumber 

func (h Hex) ToNumber() float64

ToNumber changes hexadecimal type to float64 for numeric operation. MySQL treats hexadecimal literal as double type.

func (Hex) ToString 

func (h Hex) ToString() string

ToString returns the string representation for hexadecimal literal.

type MyDecimal 

type MyDecimal struct {
	// contains filtered or unexported fields
}

MyDecimal represents a decimal value.

func ConvertDatumToDecimal 

func ConvertDatumToDecimal(d Datum) (*MyDecimal, error)

ConvertDatumToDecimal converts datum to decimal.

func NewDecFromFloatForTest 

func NewDecFromFloatForTest(f float64) *MyDecimal

NewDecFromFloatForTest creates a MyDecimal from float, as it returns no error, it should only be used in test.

func NewDecFromInt 

func NewDecFromInt(i int64) *MyDecimal

NewDecFromInt creates a MyDecimal from int.

func NewDecFromStringForTest 

func NewDecFromStringForTest(s string) *MyDecimal

NewDecFromStringForTest creates a MyDecimal from string, as it returns no error, it should only be used in test.

func NewMaxOrMinDec 

func NewMaxOrMinDec(negative bool, prec, frac int) *MyDecimal

NewMaxOrMinDec returns the max or min value decimal for given precision and fraction.

func (*MyDecimal) Compare 

func (d *MyDecimal) Compare(to *MyDecimal) int

Compare compares one decimal to another, returns -1/0/1.

func (*MyDecimal) FromBin 

func (d *MyDecimal) FromBin(bin []byte, precision, frac int) (binSize int, err error)

FromBin Restores decimal from its binary fixed-length representation.

func (*MyDecimal) FromFloat64 

func (d *MyDecimal) FromFloat64(f float64) error

FromFloat64 creates a decimal from float64 value.

func (*MyDecimal) FromInt 

func (d *MyDecimal) FromInt(val int64) *MyDecimal

FromInt sets the decimal value from int64.

func (*MyDecimal) FromString 

func (d *MyDecimal) FromString(str []byte) error

FromString parses decimal from string.

func (*MyDecimal) FromUint 

func (d *MyDecimal) FromUint(val uint64) *MyDecimal

FromUint sets the decimal value from uint64.

func (*MyDecimal) IsNegative 

func (d *MyDecimal) IsNegative() bool

IsNegative returns whether a decimal is negative.

func (*MyDecimal) PrecisionAndFrac 

func (d *MyDecimal) PrecisionAndFrac() (precision, frac int)

PrecisionAndFrac returns the internal precision and frac number.

func (*MyDecimal) Round 

func (d *MyDecimal) Round(to *MyDecimal, frac int) (err error)

Round rounds the decimal to "frac" digits. 

to     - result buffer. d == to is allowed
frac   - to what position after fraction point to round. can be negative!
mode   - round to nearest even or truncate

NOTES 

scale can be negative !
one TRUNCATED error (line XXX below) isn't treated very logical :(

RETURN VALUE 

eDecOK/eDecTruncated

func (*MyDecimal) Shift 

func (d *MyDecimal) Shift(shift int) error

Shift shifts decimal digits in given number (with rounding if it need), shift > 0 means shift to left shift, shift < 0 means right shift. In fact it is multiplying on 10^shift.

RETURN 

eDecOK          OK
eDecOverflow    operation lead to overflow, number is untoched
eDecTruncated   number was rounded to fit into buffer

func (*MyDecimal) String 

func (d *MyDecimal) String() string

String returns the decimal string representation rounded to resultFrac.

func (*MyDecimal) ToBin 

func (d *MyDecimal) ToBin(precision, frac int) ([]byte, error)

ToBin converts decimal to its binary fixed-length representation two representations of the same length can be compared with memcmp with the correct -1/0/+1 result 

  PARAMS
		precision/frac - if precision is 0, internal value of the decimal will be used,
		then the encoded value is not memory comparable.

  NOTE
    the buffer is assumed to be of the size decimalBinSize(precision, frac)

  RETURN VALUE
  	bin     - binary value
    errCode - eDecOK/eDecTruncate/eDecOverflow

  DESCRIPTION
    for storage decimal numbers are converted to the "binary" format.

    This format has the following properties:
      1. length of the binary representation depends on the {precision, frac}
      as provided by the caller and NOT on the digitsInt/digitsFrac of the decimal to
      convert.
      2. binary representations of the same {precision, frac} can be compared
      with memcmp - with the same result as DecimalCompare() of the original
      decimals (not taking into account possible precision loss during
      conversion).

    This binary format is as follows:
      1. First the number is converted to have a requested precision and frac.
      2. Every full digitsPerWord digits of digitsInt part are stored in 4 bytes
         as is
      3. The first digitsInt % digitesPerWord digits are stored in the reduced
         number of bytes (enough bytes to store this number of digits -
         see dig2bytes)
      4. same for frac - full word are stored as is,
         the last frac % digitsPerWord digits - in the reduced number of bytes.
      5. If the number is negative - every byte is inversed.
      5. The very first bit of the resulting byte array is inverted (because
         memcmp compares unsigned bytes, see property 2 above)

    Example:

      1234567890.1234

    internally is represented as 3 words

      1 234567890 123400000

    (assuming we want a binary representation with precision=14, frac=4)
    in hex it's

      00-00-00-01  0D-FB-38-D2  07-5A-EF-40

    now, middle word is full - it stores 9 decimal digits. It goes
    into binary representation as is:

      ...........  0D-FB-38-D2 ............

    First word has only one decimal digit. We can store one digit in
    one byte, no need to waste four:

                01 0D-FB-38-D2 ............

    now, last word. It's 123400000. We can store 1234 in two bytes:

                01 0D-FB-38-D2 04-D2

    So, we've packed 12 bytes number in 7 bytes.
    And now we invert the highest bit to get the final result:

                81 0D FB 38 D2 04 D2

    And for -1234567890.1234 it would be

                7E F2 04 C7 2D FB 2D

func (*MyDecimal) ToFloat64 

func (d *MyDecimal) ToFloat64() (float64, error)

ToFloat64 converts decimal to float64 value.

func (*MyDecimal) ToInt 

func (d *MyDecimal) ToInt() (int64, error)

ToInt returns int part of the decimal, returns the result and errcode.

func (*MyDecimal) ToString 

func (d *MyDecimal) ToString() (str []byte)

ToString converts decimal to its printable string representation without rounding. 

RETURN VALUE

    str       - result string
    errCode   - eDecOK/eDecTruncate/eDecOverflow

func (*MyDecimal) ToUint 

func (d *MyDecimal) ToUint() (uint64, error)

ToUint returns int part of the decimal, returns the result and errcode.

type Set 

type Set struct {
	Name  string
	Value uint64
}

Set is for MySQL Set type.

func ParseSetName 

func ParseSetName(elems []string, name string) (Set, error)

ParseSetName creates a Set with name.

func ParseSetValue 

func ParseSetValue(elems []string, number uint64) (Set, error)

ParseSetValue creates a Set with special number.

func (Set) String 

func (e Set) String() string

String implements fmt.Stringer interface.

func (Set) ToNumber 

func (e Set) ToNumber() float64

ToNumber changes Set to float64 for numeric operation.

type Time 

type Time struct {
	time.Time
	Type uint8
	// Fsp is short for Fractional Seconds Precision.
	// See http://dev.mysql.com/doc/refman/5.7/en/fractional-seconds.html
	Fsp int
}

Time is the struct for handling datetime, timestamp and date. TODO: check if need a NewTime function to set Fsp default value?

func CurrentTime 

func CurrentTime(tp uint8) Time

CurrentTime returns current time with type tp.

func ParseDate 

func ParseDate(str string) (Time, error)

ParseDate is a helper function wrapping ParseTime with date type.

func ParseDateFromNum 

func ParseDateFromNum(num int64) (Time, error)

ParseDateFromNum is a helper function wrapping ParseTimeFromNum with date type.

func ParseDatetime 

func ParseDatetime(str string) (Time, error)

ParseDatetime is a helper function wrapping ParseTime with datetime type and default fsp.

func ParseDatetimeFromNum 

func ParseDatetimeFromNum(num int64) (Time, error)

ParseDatetimeFromNum is a helper function wrapping ParseTimeFromNum with datetime type and default fsp.

func ParseTime 

func ParseTime(str string, tp byte, fsp int) (Time, error)

ParseTime parses a formatted string with type tp and specific fsp. Type is TypeDatetime, TypeTimestamp and TypeDate. Fsp is in range [0, 6]. MySQL supports many valid datatime format, but still has some limitation. If delimiter exists, the date part and time part is separated by a space or T, other punctuation character can be used as the delimiter between date parts or time parts. If no delimiter, the format must be YYYYMMDDHHMMSS or YYMMDDHHMMSS If we have fractional seconds part, we must use decimal points as the delimiter. The valid datetime range is from '1000-01-01 00:00:00.000000' to '9999-12-31 23:59:59.999999'. The valid timestamp range is from '1970-01-01 00:00:01.000000' to '2038-01-19 03:14:07.999999'. The valid date range is from '1000-01-01' to '9999-12-31'

func ParseTimeFromInt64 

func ParseTimeFromInt64(num int64) (Time, error)

ParseTimeFromInt64 parses mysql time value from int64.

func ParseTimeFromNum 

func ParseTimeFromNum(num int64, tp byte, fsp int) (Time, error)

ParseTimeFromNum parses a formatted int64, returns the value which type is tp.

func ParseTimestamp 

func ParseTimestamp(str string) (Time, error)

ParseTimestamp is a helper function wrapping ParseTime with timestamp type and default fsp.

func ParseTimestampFromNum 

func ParseTimestampFromNum(num int64) (Time, error)

ParseTimestampFromNum is a helper function wrapping ParseTimeFromNum with timestamp type and default fsp.

func (Time) Compare 

func (t Time) Compare(o Time) int

Compare returns an integer comparing the time instant t to o. If t is after o, return 1, equal o, return 0, before o, return -1.

func (Time) CompareString 

func (t Time) CompareString(str string) (int, error)

CompareString is like Compare, but parses string to Time then compares.

func (Time) Convert 

func (t Time) Convert(tp uint8) (Time, error)

Convert converts t with type tp.

func (Time) ConvertToDuration 

func (t Time) ConvertToDuration() (Duration, error)

ConvertToDuration converts mysql datetime, timestamp and date to mysql time type. e.g, 2012-12-12T10:10:10 -> 10:10:10 2012-12-12 -> 0

func (*Time) FromPackedUint 

func (t *Time) FromPackedUint(packed uint64) error

FromPackedUint decodes Time from a packed uint64 value.

func (Time) IsZero 

func (t Time) IsZero() bool

IsZero returns a boolean indicating whether the time is equal to ZeroTime.

func (Time) RoundFrac 

func (t Time) RoundFrac(fsp int) (Time, error)

RoundFrac rounds fractional seconds precision with new fsp and returns a new one. We will use the “round half up” rule, e.g, >= 0.5 -> 1, < 0.5 -> 0, so 2011:11:11 10:10:10.888888 round 0 -> 2011:11:11 10:10:11 and 2011:11:11 10:10:10.111111 round 0 -> 2011:11:11 10:10:10

func (Time) String 

func (t Time) String() string

func (Time) ToNumber 

func (t Time) ToNumber() *MyDecimal

ToNumber returns a formatted number. e.g, 2012-12-12 -> 20121212 2012-12-12T10:10:10 -> 20121212101010 2012-12-12T10:10:10.123456 -> 20121212101010.123456

func (Time) ToPackedUint 

func (t Time) ToPackedUint() uint64

ToPackedUint encodes Time to a packed uint64 value. 

 1 bit  0
17 bits year*13+month   (year 0-9999, month 0-12)
 5 bits day             (0-31)
 5 bits hour            (0-23)
 6 bits minute          (0-59)
 6 bits second          (0-59)
24 bits microseconds    (0-999999)

Total: 64 bits = 8 bytes

0YYYYYYY.YYYYYYYY.YYdddddh.hhhhmmmm.mmssssss.ffffffff.ffffffff.ffffffff

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