types

package
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 Go to latest Published: Aug 24, 2018 License: Apache-2.0 Imports: 24 Imported by: 4,903

Documentation

Index

Constants

View Source 
const (
	KindNull          byte = 0
	KindInt64         byte = 1
	KindUint64        byte = 2
	KindFloat32       byte = 3
	KindFloat64       byte = 4
	KindString        byte = 5
	KindBytes         byte = 6
	KindBinaryLiteral byte = 7 // Used for BIT / HEX literals.
	KindMysqlDecimal  byte = 8
	KindMysqlDuration byte = 9
	KindMysqlEnum     byte = 10
	KindMysqlBit      byte = 11 // Used for BIT table column values.
	KindMysqlSet      byte = 12
	KindMysqlTime     byte = 13
	KindInterface     byte = 14
	KindMinNotNull    byte = 15
	KindMaxValue      byte = 16
	KindRaw           byte = 17
	KindMysqlJSON     byte = 18
)

Kind constants.

View Source 
const (
	// UnspecifiedFsp is the unspecified fractional seconds part.
	UnspecifiedFsp = -1
	// MaxFsp is the maximum digit of fractional seconds part.
	MaxFsp = 6
	// MinFsp is the minimum digit of fractional seconds part.
	MinFsp = 0
	// DefaultFsp is the default digit of fractional seconds part.
	// MySQL use 0 as the default Fsp.
	DefaultFsp = 0
)
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
	// MaxDuration is the maximum for duration.
	MaxDuration int64 = 838*10000 + 59*100 + 59
	// MinTime is the minimum for mysql time type.
	MinTime = -gotime.Duration(838*3600+59*60+59) * gotime.Second
	// MaxTime is the maximum for mysql time type.
	MaxTime = gotime.Duration(838*3600+59*60+59) * gotime.Second
	// ZeroDatetimeStr is the string representation of a zero datetime.
	ZeroDatetimeStr = "0000-00-00 00:00:00"
	// ZeroDateStr is the string representation of a zero date.
	ZeroDateStr = "0000-00-00"

	// TimeMaxHour is the max hour for mysql time type.
	TimeMaxHour = 838
	// TimeMaxMinute is the max minute for mysql time type.
	TimeMaxMinute = 59
	// TimeMaxSecond is the max second for mysql time type.
	TimeMaxSecond = 59
	// TimeMaxValue is the maximum value for mysql time type.
	TimeMaxValue = TimeMaxHour*10000 + TimeMaxMinute*100 + TimeMaxSecond
	// TimeMaxValueSeconds is the maximum second value for mysql time type.
	TimeMaxValueSeconds = TimeMaxHour*3600 + TimeMaxMinute*60 + TimeMaxSecond
)
View Source 
const MyDecimalStructSize = 40

MyDecimalStructSize is the struct size of MyDecimal.

View Source 
const (
	UnspecifiedLength = -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")
	// ErrIllegalValueForType is returned when value of type is illegal.
	ErrIllegalValueForType = terror.ClassTypes.New(codeIllegalValueForType, mysql.MySQLErrName[mysql.ErrIllegalValueForType])
	// ErrTruncated is returned when data has been truncated during conversion.
	ErrTruncated = terror.ClassTypes.New(codeTruncated, "Data Truncated")
	// ErrTruncatedWrongVal is returned when data has been truncated during conversion.
	ErrTruncatedWrongVal = terror.ClassTypes.New(codeTruncatedWrongValue, msgTruncatedWrongVal)
	// ErrOverflow is returned when data is out of range for a field type.
	ErrOverflow = terror.ClassTypes.New(codeOverflow, msgOverflow)
	// ErrDivByZero is return when do division by 0.
	ErrDivByZero = terror.ClassTypes.New(codeDivByZero, "Division by 0")
	// ErrTooBigDisplayWidth is return when display width out of range for column.
	ErrTooBigDisplayWidth = terror.ClassTypes.New(codeTooBigDisplayWidth, "Too Big Display width")
	// ErrTooBigFieldLength is return when column length too big for column.
	ErrTooBigFieldLength = terror.ClassTypes.New(codeTooBigFieldLength, "Too Big Field length")
	// ErrTooBigSet is returned when too many strings for column.
	ErrTooBigSet = terror.ClassTypes.New(codeTooBigSet, "Too Big Set")
	// ErrTooBigScale is returned when type DECIMAL/NUMERIC scale is bigger than mysql.MaxDecimalScale.
	ErrTooBigScale = terror.ClassTypes.New(codeTooBigScale, mysql.MySQLErrName[mysql.ErrTooBigScale])
	// ErrTooBigPrecision is returned when type DECIMAL/NUMERIC precision is bigger than mysql.MaxDecimalWidth
	ErrTooBigPrecision = terror.ClassTypes.New(codeTooBigPrecision, mysql.MySQLErrName[mysql.ErrTooBigPrecision])
	// ErrWrongFieldSpec is return when incorrect column specifier for column.
	ErrWrongFieldSpec = terror.ClassTypes.New(codeWrongFieldSpec, "Wrong Field Spec")
	// ErrBadNumber is return when parsing an invalid binary decimal number.
	ErrBadNumber = terror.ClassTypes.New(codeBadNumber, "Bad Number")
	// ErrCastAsSignedOverflow is returned when positive out-of-range integer, and convert to it's negative complement.
	ErrCastAsSignedOverflow = terror.ClassTypes.New(codeUnknown, msgCastAsSignedOverflow)
	// ErrCastNegIntAsUnsigned is returned when a negative integer be casted to an unsigned int.
	ErrCastNegIntAsUnsigned = terror.ClassTypes.New(codeUnknown, msgCastNegIntAsUnsigned)
	// ErrInvalidDefault is returned when meet a invalid default value.
	ErrInvalidDefault = terror.ClassTypes.New(codeInvalidDefault, "Invalid default value for '%s'")
	// ErrMBiggerThanD is returned when precision less than the scale.
	ErrMBiggerThanD = terror.ClassTypes.New(codeMBiggerThanD, mysql.MySQLErrName[mysql.ErrMBiggerThanD])
	// ErrWarnDataOutOfRange is returned when the value in a numeric column that is outside the permissible range of the column data type.
	// See https://dev.mysql.com/doc/refman/5.5/en/out-of-range-and-overflow.html for details
	ErrWarnDataOutOfRange = terror.ClassTypes.New(codeDataOutOfRange, mysql.MySQLErrName[mysql.ErrWarnDataOutOfRange])
)
View Source 
var (
	ErrInvalidTimeFormat      = terror.ClassTypes.New(mysql.ErrTruncatedWrongValue, "invalid time format: '%v'")
	ErrInvalidYearFormat      = errors.New("invalid year format")
	ErrInvalidYear            = errors.New("invalid year")
	ErrZeroDate               = errors.New("datetime zero in date")
	ErrIncorrectDatetimeValue = terror.ClassTypes.New(mysql.ErrTruncatedWrongValue, "Incorrect datetime value: '%s'")
)

Portable analogs of some common call errors.

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

	// ZeroTime is the zero value for TimeInternal type.
	ZeroTime = MysqlTime{}

	// 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 = FromDate(1000, 1, 1, 0, 0, 0, 0)
	// MaxDatetime is the maximum for mysql datetime type.
	MaxDatetime = FromDate(9999, 12, 31, 23, 59, 59, 999999)

	// BoundTimezone is the timezone for min and max timestamp.
	BoundTimezone = gotime.UTC
	// MinTimestamp is the minimum for mysql timestamp type.
	MinTimestamp = Time{
		Time: FromDate(1970, 1, 1, 0, 0, 1, 0),
		Type: mysql.TypeTimestamp,
		Fsp:  DefaultFsp,
	}

	// 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 SignedLowerBound = map[byte]int64{
	mysql.TypeTiny:     math.MinInt8,
	mysql.TypeShort:    math.MinInt16,
	mysql.TypeInt24:    mysql.MinInt24,
	mysql.TypeLong:     math.MinInt32,
	mysql.TypeLonglong: math.MinInt64,
}

SignedLowerBound indicates the min int64 values of different mysql types.

View Source 
var SignedUpperBound = map[byte]int64{
	mysql.TypeTiny:     math.MaxInt8,
	mysql.TypeShort:    math.MaxInt16,
	mysql.TypeInt24:    mysql.MaxInt24,
	mysql.TypeLong:     math.MaxInt32,
	mysql.TypeLonglong: math.MaxInt64,
}

SignedUpperBound indicates the max int64 values of different mysql types.

View Source 
var UnsignedUpperBound = map[byte]uint64{
	mysql.TypeTiny:     math.MaxUint8,
	mysql.TypeShort:    math.MaxUint16,
	mysql.TypeInt24:    mysql.MaxUint24,
	mysql.TypeLong:     math.MaxUint32,
	mysql.TypeLonglong: math.MaxUint64,
	mysql.TypeBit:      math.MaxUint64,
	mysql.TypeEnum:     math.MaxUint64,
	mysql.TypeSet:      math.MaxUint64,
}

UnsignedUpperBound indicates the max uint64 values of different mysql types.

View Source 
var ZeroBinaryLiteral = BinaryLiteral{}

ZeroBinaryLiteral is a BinaryLiteral literal with zero value.

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 CheckFsp 

func CheckFsp(fsp int) (int, error)

CheckFsp checks whether fsp is in valid range.

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 ConvertFloatToInt 

func ConvertFloatToInt(fval float64, lowerBound, upperBound int64, tp byte) (int64, error)

ConvertFloatToInt converts a float64 value to a int value.

func ConvertFloatToUint 

func ConvertFloatToUint(fval float64, upperBound uint64, tp byte) (uint64, error)

ConvertFloatToUint converts a float value to an uint value.

func ConvertIntToInt 

func ConvertIntToInt(val int64, lowerBound int64, upperBound int64, tp byte) (int64, error)

ConvertIntToInt converts an int value to another int value of different precision.

func ConvertIntToUint 

func ConvertIntToUint(val int64, upperBound uint64, tp byte) (uint64, error)

ConvertIntToUint converts an int value to an uint value.

func ConvertJSONToFloat 

func ConvertJSONToFloat(sc *stmtctx.StatementContext, j json.BinaryJSON) (float64, error)

ConvertJSONToFloat casts JSON into float64.

func ConvertJSONToInt 

func ConvertJSONToInt(sc *stmtctx.StatementContext, j json.BinaryJSON, unsigned bool) (int64, error)

ConvertJSONToInt casts JSON into int64.

func ConvertUintToInt 

func ConvertUintToInt(val uint64, upperBound int64, tp byte) (int64, error)

ConvertUintToInt converts an uint value to an int value.

func ConvertUintToUint 

func ConvertUintToUint(val uint64, upperBound uint64, tp byte) (uint64, error)

ConvertUintToUint converts an uint value to another uint value of different precision.

func DateDiff 

func DateDiff(startTime, endTime MysqlTime) int

DateDiff calculates number of days between two days.

func DateFSP 

func DateFSP(date string) (fsp int)

DateFSP gets fsp from date string.

func DatumsToStrNoErr 

func DatumsToStrNoErr(datums []Datum) string

DatumsToStrNoErr converts some datums to a formatted string. If an error occurs, it will print a log instead of returning an error.

func DatumsToString 

func DatumsToString(datums []Datum, handleSpecialValue bool) (string, error)

DatumsToString converts several datums to formatted string.

func DecimalAdd 

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

DecimalAdd adds two decimals, sets the result to 'to'. Note: DO NOT use `from1` or `from2` as `to` since the metadata of `to` may be changed during evaluating.

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 DefaultParamTypeForValue 

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

DefaultParamTypeForValue returns the default FieldType for the parameterized value.

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(sc *stmtctx.StatementContext, a []Datum, b []Datum) (bool, error)

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

func ExtractDatetimeNum 

func ExtractDatetimeNum(t *Time, unit string) (int64, error)

ExtractDatetimeNum extracts time value number from datetime unit and format.

func ExtractDurationNum 

func ExtractDurationNum(d *Duration, unit string) (int64, error)

ExtractDurationNum extracts duration value number from duration unit and format.

func ExtractTimeValue 

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

ExtractTimeValue extracts time value from time unit and format.

func GetFormatType 

func GetFormatType(format string) (isDuration, isDate bool)

GetFormatType checks the type(Duration, Date or Datetime) of a format string.

func GetFsp 

func GetFsp(s string) (fsp int)

GetFsp gets the fsp of a string.

func InvOp2 

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

InvOp2 returns an invalid operation error.

func IsBinaryStr 

func IsBinaryStr(ft *FieldType) bool

IsBinaryStr returns a boolean indicating whether the field type is a binary string type.

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 IsNonBinaryStr 

func IsNonBinaryStr(ft *FieldType) bool

IsNonBinaryStr returns a boolean indicating whether the field type is a non-binary string type.

func IsString 

func IsString(tp byte) bool

IsString returns a boolean indicating whether the field type is a string type.

func IsTemporalWithDate 

func IsTemporalWithDate(tp byte) bool

IsTemporalWithDate returns a boolean indicating whether the tp is time type with 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 IsTypeFractionable 

func IsTypeFractionable(tp byte) bool

IsTypeFractionable returns a boolean indicating whether the tp can has time fraction.

func IsTypeNumeric 

func IsTypeNumeric(tp byte) bool

IsTypeNumeric returns a boolean indicating whether the tp is numeric type.

func IsTypePrefixable 

func IsTypePrefixable(tp byte) bool

IsTypePrefixable returns a boolean indicating whether an index on a column with the tp can be defined with a prefix.

func IsTypeTemporal 

func IsTypeTemporal(tp byte) bool

IsTypeTemporal checks if a type is a temporal type.

func IsTypeTime 

func IsTypeTime(tp byte) bool

IsTypeTime returns a boolean indicating whether the tp is time type like datetime, date or timestamp.

func IsTypeUnspecified 

func IsTypeUnspecified(tp byte) bool

IsTypeUnspecified returns a boolean indicating whether the tp is the Unspecified type.

func IsTypeVarchar 

func IsTypeVarchar(tp byte) bool

IsTypeVarchar returns a boolean indicating whether the tp is the varchar type like a varstring type or a varchar type.

func KindStr 

func KindStr(kind byte) (r string)

KindStr converts kind to a string.

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 ParseDateFormat 

func ParseDateFormat(format string) []string

ParseDateFormat parses a formatted date string and returns separated components.

func ParseFrac 

func ParseFrac(s string, fsp int) (v int, overflow bool, err error)

ParseFrac parses the input string according to fsp, returns the microsecond, and also a bool value to indice overflow. eg: "999" fsp=2 will overflow.

func ParseYear 

func ParseYear(str string) (int16, error)

ParseYear parses a formatted string and returns a year number.

func ProduceFloatWithSpecifiedTp 

func ProduceFloatWithSpecifiedTp(f float64, target *FieldType, sc *stmtctx.StatementContext) (_ float64, err error)

ProduceFloatWithSpecifiedTp produces a new float64 according to `flen` and `decimal`.

func ProduceStrWithSpecifiedTp 

func ProduceStrWithSpecifiedTp(s string, tp *FieldType, sc *stmtctx.StatementContext) (_ string, err error)

ProduceStrWithSpecifiedTp produces a new string according to `flen` and `chs`.

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 RoundFrac 

func RoundFrac(t gotime.Time, fsp int) (gotime.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 SetBinChsClnFlag 

func SetBinChsClnFlag(ft *FieldType)

SetBinChsClnFlag sets charset, collation as 'binary' and adds binaryFlag to FieldType.

func SortDatums 

func SortDatums(sc *stmtctx.StatementContext, datums []Datum) error

SortDatums sorts a slice of datum.

func StrToDuration 

func StrToDuration(sc *stmtctx.StatementContext, str string, fsp int) (d Duration, t Time, isDuration bool, err error)

StrToDuration converts str to Duration. It returns Duration in normal case, and returns Time when str is in datetime format. when isDuration is true, the d is returned, when it is false, the t is returned. See https://dev.mysql.com/doc/refman/5.5/en/date-and-time-literals.html.

func StrToFloat 

func StrToFloat(sc *stmtctx.StatementContext, str string) (float64, error)

StrToFloat converts a string to a float64 at the best-effort.

func StrToInt 

func StrToInt(sc *stmtctx.StatementContext, str string) (int64, error)

StrToInt converts a string to an integer at the best-effort.

func StrToUint 

func StrToUint(sc *stmtctx.StatementContext, str string) (uint64, error)

StrToUint converts a string to an unsigned integer at the best-effortt.

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 TimestampDiff 

func TimestampDiff(unit string, t1 Time, t2 Time) int64

TimestampDiff returns t2 - t1 where t1 and t2 are date or datetime expressions. The unit for the result (an integer) is given by the unit argument. The legal values for unit are "YEAR" "QUARTER" "MONTH" "DAY" "HOUR" "SECOND" and so on.

func ToString 

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

ToString converts an interface to a string.

func Truncate 

func Truncate(f float64, dec int) float64

Truncate truncates 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 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 TruncateOverflowMySQLTime 

func TruncateOverflowMySQLTime(d gotime.Duration) (gotime.Duration, error)

TruncateOverflowMySQLTime truncates d when it overflows, and return ErrTruncatedWrongVal.

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 BinaryLiteral 

type BinaryLiteral []byte

BinaryLiteral is the internal type for storing bit / hex literal type.

func NewBinaryLiteralFromUint 

func NewBinaryLiteralFromUint(value uint64, byteSize int) BinaryLiteral

NewBinaryLiteralFromUint creates a new BinaryLiteral instance by the given uint value in BitEndian. byteSize will be used as the length of the new BinaryLiteral, with leading bytes filled to zero. If byteSize is -1, the leading zeros in new BinaryLiteral will be trimmed.

func ParseBitStr 

func ParseBitStr(s string) (BinaryLiteral, error)

ParseBitStr parses bit string. The string format can be b'val', B'val' or 0bval, val must be 0 or 1. See https://dev.mysql.com/doc/refman/5.7/en/bit-value-literals.html

func ParseHexStr 

func ParseHexStr(s string) (BinaryLiteral, error)

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

func (BinaryLiteral) Compare 

func (b BinaryLiteral) Compare(b2 BinaryLiteral) int

Compare compares BinaryLiteral to another one

func (BinaryLiteral) String 

func (b BinaryLiteral) String() string

String implements fmt.Stringer interface.

func (BinaryLiteral) ToBitLiteralString 

func (b BinaryLiteral) ToBitLiteralString(trimLeadingZero bool) string

ToBitLiteralString returns the bit literal representation for the literal.

func (BinaryLiteral) ToInt 

func (b BinaryLiteral) ToInt(sc *stmtctx.StatementContext) (uint64, error)

ToInt returns the int value for the literal.

func (BinaryLiteral) ToString 

func (b BinaryLiteral) ToString() string

ToString returns the string representation for the literal.

type BitLiteral 

type BitLiteral BinaryLiteral

BitLiteral is the bit literal type.

func NewBitLiteral 

func NewBitLiteral(s string) (BitLiteral, error)

NewBitLiteral parses bit string as BitLiteral 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 CoerceDatum 

func CoerceDatum(sc *stmtctx.StatementContext, 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 ComputePlus 

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

ComputePlus computes the result of a+b.

func CopyDatum 

func CopyDatum(datum Datum) Datum

CopyDatum returns a new copy of the datum. TODO: Abandon this function.

func CopyRow 

func CopyRow(dr []Datum) []Datum

CopyRow deep copies a Datum slice.

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 NewBinaryLiteralDatum 

func NewBinaryLiteralDatum(b BinaryLiteral) (d Datum)

NewBinaryLiteralDatum creates a new BinaryLiteral Datum for a BinaryLiteral 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 NewMysqlBitDatum 

func NewMysqlBitDatum(b BinaryLiteral) (d Datum)

NewMysqlBitDatum creates a new MysqlBit Datum for a BinaryLiteral value.

func NewStringDatum 

func NewStringDatum(s string) (d Datum)

NewStringDatum creates a new Datum from a string.

func NewTimeDatum 

func NewTimeDatum(t Time) (d Datum)

NewTimeDatum creates a new Time from a Time value.

func NewUintDatum 

func NewUintDatum(i uint64) (d Datum)

NewUintDatum creates a new Datum from an uint64 value.

func (*Datum) Collation 

func (d *Datum) Collation() byte

Collation gets the collation of the datum.

func (*Datum) CompareDatum 

func (d *Datum) CompareDatum(sc *stmtctx.StatementContext, ad *Datum) (int, error)

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

func (*Datum) ConvertTo 

func (d *Datum) ConvertTo(sc *stmtctx.StatementContext, target *FieldType) (Datum, error)

ConvertTo converts a datum to the target field type.

func (*Datum) Copy 

func (d *Datum) Copy() *Datum

Copy deep copies a Datum.

func (*Datum) Frac 

func (d *Datum) Frac() int

Frac gets the frac of the datum.

func (*Datum) GetBinaryLiteral 

func (d *Datum) GetBinaryLiteral() BinaryLiteral

GetBinaryLiteral gets Bit value

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() BinaryLiteral

GetMysqlBit gets MysqlBit 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) GetMysqlJSON 

func (d *Datum) GetMysqlJSON() json.BinaryJSON

GetMysqlJSON gets json.BinaryJSON 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) GetRaw 

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

GetRaw gets raw 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) SetBinaryLiteral 

func (d *Datum) SetBinaryLiteral(b BinaryLiteral)

SetBinaryLiteral sets Bit value

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 BinaryLiteral)

SetMysqlBit sets MysqlBit 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) SetMysqlJSON 

func (d *Datum) SetMysqlJSON(b json.BinaryJSON)

SetMysqlJSON sets json.BinaryJSON 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) SetRaw 

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

SetRaw sets raw 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(sc *stmtctx.StatementContext) (int64, error)

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

func (*Datum) ToBytes 

func (d *Datum) ToBytes() ([]byte, error)

ToBytes gets the bytes representation of the datum.

func (*Datum) ToDecimal 

func (d *Datum) ToDecimal(sc *stmtctx.StatementContext) (*MyDecimal, error)

ToDecimal converts to a decimal.

func (*Datum) ToFloat64 

func (d *Datum) ToFloat64(sc *stmtctx.StatementContext) (float64, error)

ToFloat64 converts to a float64

func (*Datum) ToInt64 

func (d *Datum) ToInt64(sc *stmtctx.StatementContext) (int64, error)

ToInt64 converts to a int64.

func (*Datum) ToMysqlJSON 

func (d *Datum) ToMysqlJSON() (j json.BinaryJSON, err error)

ToMysqlJSON is similar to convertToMysqlJSON, except the latter parses from string, but the former uses it as primitive.

func (*Datum) ToString 

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

ToString gets the string representation of the datum.

type Duration 

type Duration struct {
	gotime.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 NumberToDuration 

func NumberToDuration(number int64, fsp int) (Duration, error)

NumberToDuration converts number to Duration.

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) Add 

func (d Duration) Add(v Duration) (Duration, error)

Add adds d to d, returns a duration value.

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(sc *stmtctx.StatementContext, str string) (int, error)

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

func (Duration) ConvertToTime 

func (d Duration) ConvertToTime(sc *stmtctx.StatementContext, 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) Sub 

func (d Duration) Sub(v Duration) (Duration, error)

Sub subtracts d to d, returns a duration value.

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 EvalType 

type EvalType byte

EvalType indicates the specified types that arguments and result of a built-in function should be. 

const (
	// ETInt represents type INT in evaluation.
	ETInt EvalType = iota
	// ETReal represents type REAL in evaluation.
	ETReal
	// ETDecimal represents type DECIMAL in evaluation.
	ETDecimal
	// ETString represents type STRING in evaluation.
	ETString
	// ETDatetime represents type DATETIME in evaluation.
	ETDatetime
	// ETTimestamp represents type TIMESTAMP in evaluation.
	ETTimestamp
	// ETDuration represents type DURATION in evaluation.
	ETDuration
	// ETJson represents type JSON in evaluation.
	ETJson
)

func AggregateEvalType 

func AggregateEvalType(fts []*FieldType, flag *uint) EvalType

AggregateEvalType aggregates arguments' EvalType of a multi-argument function.

func (EvalType) IsStringKind 

func (et EvalType) IsStringKind() bool

IsStringKind returns true for ETString, ETDatetime, ETTimestamp, ETDuration, ETJson EvalTypes.

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 AggFieldType 

func AggFieldType(tps []*FieldType) *FieldType

AggFieldType aggregates field types for a multi-argument function like `IF`, `IFNULL`, `COALESCE` whose return type is determined by the arguments' FieldTypes. Aggregation is performed by MergeFieldType function.

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) Equal 

func (ft *FieldType) Equal(other *FieldType) bool

Equal checks whether two FieldType objects are equal.

func (*FieldType) EvalType 

func (ft *FieldType) EvalType() EvalType

EvalType gets the type in evaluation.

func (*FieldType) FormatAsCastType 

func (ft *FieldType) FormatAsCastType(w io.Writer)

FormatAsCastType is used for write AST back to string.

func (*FieldType) Hybrid 

func (ft *FieldType) Hybrid() bool

Hybrid checks whether a type is a hybrid type, which can represent different types of value in specific context.

func (*FieldType) InfoSchemaStr 

func (ft *FieldType) InfoSchemaStr() string

InfoSchemaStr joins the CompactStr with unsigned flag and returns a string.

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. Note: when flen or decimal is unspecified, this function will use the default value instead of -1.

type HexLiteral 

type HexLiteral BinaryLiteral

HexLiteral is the hex literal type.

func NewHexLiteral 

func NewHexLiteral(s string) (HexLiteral, error)

NewHexLiteral parses hexadecimal string as HexLiteral type.

type MyDecimal 

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

MyDecimal represents a decimal value.

func ConvertDatumToDecimal 

func ConvertDatumToDecimal(sc *stmtctx.StatementContext, d Datum) (*MyDecimal, error)

ConvertDatumToDecimal converts datum to decimal.

func DecimalNeg 

func DecimalNeg(from *MyDecimal) *MyDecimal

DecimalNeg reverses decimal's sign.

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 NewDecFromUint 

func NewDecFromUint(i uint64) *MyDecimal

NewDecFromUint creates a MyDecimal from uint.

func NewMaxOrMinDec 

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

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

func ProduceDecWithSpecifiedTp 

func ProduceDecWithSpecifiedTp(dec *MyDecimal, tp *FieldType, sc *stmtctx.StatementContext) (_ *MyDecimal, err error)

ProduceDecWithSpecifiedTp produces a new decimal according to `flen` and `decimal`.

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) GetDigitsFrac 

func (d *MyDecimal) GetDigitsFrac() int8

GetDigitsFrac returns the digitsFrac.

func (*MyDecimal) IsNegative 

func (d *MyDecimal) IsNegative() bool

IsNegative returns whether a decimal is negative.

func (*MyDecimal) IsZero 

func (d *MyDecimal) IsZero() bool

IsZero checks whether it's a zero decimal.

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, roundMode RoundMode) (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!
   roundMode		- round to nearest even or truncate
			ModeHalfEven rounds normally.
			Truncate just truncates the decimal.

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 MysqlTime 

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

MysqlTime is the internal struct type for Time.

func FromDate 

func FromDate(year int, month int, day int, hour int, minute int, second int, microsecond int) MysqlTime

FromDate makes a internal time representation from the given date.

func FromGoTime 

func FromGoTime(t gotime.Time) MysqlTime

FromGoTime translates time.Time to mysql time internal representation.

func (MysqlTime) Day 

func (t MysqlTime) Day() int

Day returns the day value.

func (MysqlTime) GoTime 

func (t MysqlTime) GoTime(loc *gotime.Location) (gotime.Time, error)

GoTime converts MysqlTime to GoTime.

func (MysqlTime) Hour 

func (t MysqlTime) Hour() int

Hour returns the hour value.

func (MysqlTime) IsLeapYear 

func (t MysqlTime) IsLeapYear() bool

IsLeapYear returns if it's leap year.

func (MysqlTime) Microsecond 

func (t MysqlTime) Microsecond() int

Microsecond returns the microsecond value.

func (MysqlTime) Minute 

func (t MysqlTime) Minute() int

Minute returns the minute value.

func (MysqlTime) Month 

func (t MysqlTime) Month() int

Month returns the month value.

func (MysqlTime) Second 

func (t MysqlTime) Second() int

Second returns the second value.

func (MysqlTime) Week 

func (t MysqlTime) Week(mode int) int

Week returns the week value.

func (MysqlTime) Weekday 

func (t MysqlTime) Weekday() gotime.Weekday

Weekday returns the Weekday value.

func (MysqlTime) Year 

func (t MysqlTime) Year() int

Year returns the year value.

func (MysqlTime) YearDay 

func (t MysqlTime) YearDay() int

YearDay returns day in year.

func (MysqlTime) YearWeek 

func (t MysqlTime) YearWeek(mode int) (int, int)

YearWeek return year and week.

type RoundMode 

type RoundMode string

RoundMode is the type for round mode. 

const (
	DivFracIncr = 4

	// ModeHalfEven rounds normally.
	ModeHalfEven RoundMode = "ModeHalfEven"
	// Truncate just truncates the decimal.
	ModeTruncate RoundMode = "Truncate"
)

constant values.

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 MysqlTime
	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 MaxMySQLTime 

func MaxMySQLTime(fsp int) Time

MaxMySQLTime returns Time with maximum mysql time type.

func ParseDate 

func ParseDate(sc *stmtctx.StatementContext, str string) (Time, error)

ParseDate is a helper function wrapping ParseTime with date type.

func ParseDateFromNum 

func ParseDateFromNum(sc *stmtctx.StatementContext, num int64) (Time, error)

ParseDateFromNum is a helper function wrapping ParseTimeFromNum with date type.

func ParseDatetime 

func ParseDatetime(sc *stmtctx.StatementContext, str string) (Time, error)

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

func ParseDatetimeFromNum 

func ParseDatetimeFromNum(sc *stmtctx.StatementContext, num int64) (Time, error)

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

func ParseTime 

func ParseTime(sc *stmtctx.StatementContext, 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 datetime 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 ParseTimeFromFloatString 

func ParseTimeFromFloatString(sc *stmtctx.StatementContext, str string, tp byte, fsp int) (Time, error)

ParseTimeFromFloatString is similar to ParseTime, except that it's used to parse a float converted string.

func ParseTimeFromInt64 

func ParseTimeFromInt64(sc *stmtctx.StatementContext, num int64) (Time, error)

ParseTimeFromInt64 parses mysql time value from int64.

func ParseTimeFromNum 

func ParseTimeFromNum(sc *stmtctx.StatementContext, num int64, tp byte, fsp int) (Time, error)

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

func ParseTimestamp 

func ParseTimestamp(sc *stmtctx.StatementContext, str string) (Time, error)

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

func ParseTimestampFromNum 

func ParseTimestampFromNum(sc *stmtctx.StatementContext, num int64) (Time, error)

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

func StrToDateTime 

func StrToDateTime(sc *stmtctx.StatementContext, str string, fsp int) (Time, error)

StrToDateTime converts str to MySQL DateTime.

func TimeFromDays 

func TimeFromDays(num int64) Time

TimeFromDays Converts a day number to a date.

func (*Time) Add 

func (t *Time) Add(sc *stmtctx.StatementContext, d Duration) (Time, error)

Add adds d to t, returns the result time value.

func (*Time) Check 

func (t *Time) Check(sc *stmtctx.StatementContext) error

Check if 't' is valid

func (Time) Clock 

func (t Time) Clock() (hour int, minute int, second int)

Clock returns the hour, minute, and second within the day specified by t.

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(sc *stmtctx.StatementContext, str string) (int, error)

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

func (Time) Convert 

func (t Time) Convert(sc *stmtctx.StatementContext, tp uint8) (Time, error)

Convert converts t with type tp.

func (*Time) ConvertTimeZone 

func (t *Time) ConvertTimeZone(from, to *gotime.Location) error

ConvertTimeZone converts the time value from one timezone to another. The input time should be a valid timestamp.

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) DateFormat 

func (t Time) DateFormat(layout string) (string, error)

DateFormat returns a textual representation of the time value formatted according to layout. See http://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-format

func (*Time) FromPackedUint 

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

FromPackedUint decodes Time from a packed uint64 value.

func (Time) InvalidZero 

func (t Time) InvalidZero() bool

InvalidZero returns a boolean indicating whether the month or day is zero.

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(sc *stmtctx.StatementContext, fsp int) (Time, error)

RoundFrac rounds the fraction part of a time-type value according to `fsp`.

func (*Time) StrToDate 

func (t *Time) StrToDate(sc *stmtctx.StatementContext, date, format string) bool

StrToDate converts date string according to format. See https://dev.mysql.com/doc/refman/5.7/en/date-and-time-functions.html#function_date-format

func (Time) String 

func (t Time) String() string

func (*Time) Sub 

func (t *Time) Sub(sc *stmtctx.StatementContext, t1 *Time) Duration

Sub subtracts t1 from t, returns a duration value. Note that sub should not be done on different time types.

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, error)

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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