null

README

null

import "gopkg.in/guregu/null.v3"

null is a library with reasonable options for dealing with nullable SQL and JSON values

There are two packages: null and its subpackage zero.

Types in null will only be considered null on null input, and will JSON encode to null. If you need zero and null be considered separate values, use these.

Types in zero are treated like zero values in Go: blank string input will produce a null zero.String, and null Strings will JSON encode to "". Zero values of these types will be considered null to SQL. If you need zero and null treated the same, use these.

All types implement sql.Scanner and driver.Valuer, so you can use this library in place of sql.NullXXX. All types also implement: encoding.TextMarshaler, encoding.TextUnmarshaler, json.Marshaler, and json.Unmarshaler.

null package

import "gopkg.in/guregu/null.v3"

null.String

Nullable string.

Marshals to JSON null if SQL source data is null. Zero (blank) input will not produce a null String. Can unmarshal from sql.NullString JSON input or string input.

null.Int

Nullable int64.

Marshals to JSON null if SQL source data is null. Zero input will not produce a null Int. Can unmarshal from sql.NullInt64 JSON input.

null.Float

Nullable float64.

Marshals to JSON null if SQL source data is null. Zero input will not produce a null Float. Can unmarshal from sql.NullFloat64 JSON input.

null.Bool

Nullable bool.

Marshals to JSON null if SQL source data is null. False input will not produce a null Bool. Can unmarshal from sql.NullBool JSON input.

null.Time

Marshals to JSON null if SQL source data is null. Uses time.Time's marshaler. Can unmarshal from pq.NullTime and similar JSON input.

zero package

import "gopkg.in/guregu/null.v3/zero"

zero.String

Nullable string.

Will marshal to a blank string if null. Blank string input produces a null String. Null values and zero values are considered equivalent. Can unmarshal from sql.NullString JSON input.

zero.Int

Nullable int64.

Will marshal to 0 if null. 0 produces a null Int. Null values and zero values are considered equivalent. Can unmarshal from sql.NullInt64 JSON input.

zero.Float

Nullable float64.

Will marshal to 0 if null. 0.0 produces a null Float. Null values and zero values are considered equivalent. Can unmarshal from sql.NullFloat64 JSON input.

zero.Bool

Nullable bool.

Will marshal to false if null. false produces a null Float. Null values and zero values are considered equivalent. Can unmarshal from sql.NullBool JSON input.

zero.Time

Will marshal to the zero time if null. Uses time.Time's marshaler. Can unmarshal from pq.NullTime and similar JSON input.

Bugs

json's ",omitempty" struct tag does not work correctly right now. It will never omit a null or empty String. This might be fixed eventually.

License

BSD

Documentation

Overview

Package null contains SQL types that consider zero input and null input as separate values, with convenient support for JSON and text marshaling. Types in this package will always encode to their null value if null. Use the zero subpackage if you want zero values and null to be treated the same.

Index

• type Bool
  • func BoolFrom(b bool) Bool
  • func BoolFromPtr(b *bool) Bool
  • func NewBool(b bool, valid bool) Bool
  • func (b Bool) Equal(other Bool) bool
  • func (b Bool) IsZero() bool
  • func (b Bool) MarshalJSON() ([]byte, error)
  • func (b Bool) MarshalText() ([]byte, error)
  • func (b Bool) Ptr() *bool
  • func (b *Bool) SetValid(v bool)
  • func (b *Bool) UnmarshalJSON(data []byte) error
  • func (b *Bool) UnmarshalText(text []byte) error
  • func (b Bool) ValueOrZero() bool
• type Float
  • func FloatFrom(f float64) Float
  • func FloatFromPtr(f *float64) Float
  • func NewFloat(f float64, valid bool) Float
  • func (f Float) Equal(other Float) bool
  • func (f Float) IsZero() bool
  • func (f Float) MarshalJSON() ([]byte, error)
  • func (f Float) MarshalText() ([]byte, error)
  • func (f Float) Ptr() *float64
  • func (f *Float) SetValid(n float64)
  • func (f *Float) UnmarshalJSON(data []byte) error
  • func (f *Float) UnmarshalText(text []byte) error
  • func (f Float) ValueOrZero() float64
• type Int
  • func IntFrom(i int64) Int
  • func IntFromPtr(i *int64) Int
  • func NewInt(i int64, valid bool) Int
  • func (i Int) Equal(other Int) bool
  • func (i Int) IsZero() bool
  • func (i Int) MarshalJSON() ([]byte, error)
  • func (i Int) MarshalText() ([]byte, error)
  • func (i Int) Ptr() *int64
  • func (i *Int) SetValid(n int64)
  • func (i *Int) UnmarshalJSON(data []byte) error
  • func (i *Int) UnmarshalText(text []byte) error
  • func (i Int) ValueOrZero() int64
• type String
  • func NewString(s string, valid bool) String
  • func StringFrom(s string) String
  • func StringFromPtr(s *string) String
  • func (s String) Equal(other String) bool
  • func (s String) IsZero() bool
  • func (s String) MarshalJSON() ([]byte, error)
  • func (s String) MarshalText() ([]byte, error)
  • func (s String) Ptr() *string
  • func (s *String) SetValid(v string)
  • func (s *String) UnmarshalJSON(data []byte) error
  • func (s *String) UnmarshalText(text []byte) error
  • func (s String) ValueOrZero() string
• type Time
  • func NewTime(t time.Time, valid bool) Time
  • func TimeFrom(t time.Time) Time
  • func TimeFromPtr(t *time.Time) Time
  • func (t Time) Equal(other Time) bool
  • func (t Time) ExactEqual(other Time) bool
  • func (t Time) IsZero() bool
  • func (t Time) MarshalJSON() ([]byte, error)
  • func (t Time) MarshalText() ([]byte, error)
  • func (t Time) Ptr() *time.Time
  • func (t *Time) Scan(value interface{}) error
  • func (t *Time) SetValid(v time.Time)
  • func (t *Time) UnmarshalJSON(data []byte) error
  • func (t *Time) UnmarshalText(text []byte) error
  • func (t Time) Value() (driver.Value, error)
  • func (t Time) ValueOrZero() time.Time

Types

type Bool

type Bool struct {
	sql.NullBool
}

Bool is a nullable bool. It does not consider false values to be null. It will decode to null, not false, if null.

func BoolFrom

func BoolFrom(b bool) Bool

BoolFrom creates a new Bool that will always be valid.

func BoolFromPtr

func BoolFromPtr(b *bool) Bool

BoolFromPtr creates a new Bool that will be null if f is nil.

func NewBool

func NewBool(b bool, valid bool) Bool

NewBool creates a new Bool

func (Bool) Equal

func (b Bool) Equal(other Bool) bool

Equal returns true if both booleans have the same value or are both null.

func (Bool) IsZero

func (b Bool) IsZero() bool

IsZero returns true for invalid Bools, for future omitempty support (Go 1.4?) A non-null Bool with a 0 value will not be considered zero.

func (Bool) MarshalJSON

func (b Bool) MarshalJSON() ([]byte, error)

MarshalJSON implements json.Marshaler. It will encode null if this Bool is null.

func (Bool) MarshalText

func (b Bool) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler. It will encode a blank string if this Bool is null.

func (Bool) Ptr

func (b Bool) Ptr() *bool

Ptr returns a pointer to this Bool's value, or a nil pointer if this Bool is null.

func (*Bool) SetValid

func (b *Bool) SetValid(v bool)

SetValid changes this Bool's value and also sets it to be non-null.

func (*Bool) UnmarshalJSON

func (b *Bool) UnmarshalJSON(data []byte) error

UnmarshalJSON implements json.Unmarshaler. It supports number and null input. 0 will not be considered a null Bool. It also supports unmarshalling a sql.NullBool.

func (*Bool) UnmarshalText

func (b *Bool) UnmarshalText(text []byte) error

UnmarshalText implements encoding.TextUnmarshaler. It will unmarshal to a null Bool if the input is a blank or not an integer. It will return an error if the input is not an integer, blank, or "null".

func (Bool) ValueOrZero

func (b Bool) ValueOrZero() bool

ValueOrZero returns the inner value if valid, otherwise false.

type Float

type Float struct {
	sql.NullFloat64
}

Float is a nullable float64. It does not consider zero values to be null. It will decode to null, not zero, if null.

func FloatFrom

func FloatFrom(f float64) Float

FloatFrom creates a new Float that will always be valid.

func FloatFromPtr

func FloatFromPtr(f *float64) Float

FloatFromPtr creates a new Float that be null if f is nil.

func NewFloat

func NewFloat(f float64, valid bool) Float

NewFloat creates a new Float

func (Float) Equal

func (f Float) Equal(other Float) bool

Equal returns true if both floats have the same value or are both null. Warning: calculations using floating point numbers can result in different ways the numbers are stored in memory. Therefore, this function is not suitable to compare the result of a calculation. Use this method only to check if the value has changed in comparison to some previous value.

func (Float) IsZero

func (f Float) IsZero() bool

IsZero returns true for invalid Floats, for future omitempty support (Go 1.4?) A non-null Float with a 0 value will not be considered zero.

func (Float) MarshalJSON

func (f Float) MarshalJSON() ([]byte, error)

MarshalJSON implements json.Marshaler. It will encode null if this Float is null.

func (Float) MarshalText

func (f Float) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler. It will encode a blank string if this Float is null.

func (Float) Ptr

func (f Float) Ptr() *float64

Ptr returns a pointer to this Float's value, or a nil pointer if this Float is null.

func (*Float) SetValid

func (f *Float) SetValid(n float64)

SetValid changes this Float's value and also sets it to be non-null.

func (*Float) UnmarshalJSON

func (f *Float) UnmarshalJSON(data []byte) error

UnmarshalJSON implements json.Unmarshaler. It supports number and null input. 0 will not be considered a null Float. It also supports unmarshalling a sql.NullFloat64.

func (*Float) UnmarshalText

func (f *Float) UnmarshalText(text []byte) error

UnmarshalText implements encoding.TextUnmarshaler. It will unmarshal to a null Float if the input is a blank or not an integer. It will return an error if the input is not an integer, blank, or "null".

func (Float) ValueOrZero

func (f Float) ValueOrZero() float64

ValueOrZero returns the inner value if valid, otherwise zero.

type Int

type Int struct {
	sql.NullInt64
}

Int is an nullable int64. It does not consider zero values to be null. It will decode to null, not zero, if null.

func IntFrom

func IntFrom(i int64) Int

IntFrom creates a new Int that will always be valid.

func IntFromPtr

func IntFromPtr(i *int64) Int

IntFromPtr creates a new Int that be null if i is nil.

func NewInt

func NewInt(i int64, valid bool) Int

NewInt creates a new Int

func (Int) Equal

func (i Int) Equal(other Int) bool

Equal returns true if both ints have the same value or are both null.

func (Int) IsZero

func (i Int) IsZero() bool

IsZero returns true for invalid Ints, for future omitempty support (Go 1.4?) A non-null Int with a 0 value will not be considered zero.

func (Int) MarshalJSON

func (i Int) MarshalJSON() ([]byte, error)

MarshalJSON implements json.Marshaler. It will encode null if this Int is null.

func (Int) MarshalText

func (i Int) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler. It will encode a blank string if this Int is null.

func (Int) Ptr

func (i Int) Ptr() *int64

Ptr returns a pointer to this Int's value, or a nil pointer if this Int is null.

func (*Int) SetValid

func (i *Int) SetValid(n int64)

SetValid changes this Int's value and also sets it to be non-null.

func (*Int) UnmarshalJSON

func (i *Int) UnmarshalJSON(data []byte) error

UnmarshalJSON implements json.Unmarshaler. It supports number and null input. 0 will not be considered a null Int. It also supports unmarshalling a sql.NullInt64.

func (*Int) UnmarshalText

func (i *Int) UnmarshalText(text []byte) error

UnmarshalText implements encoding.TextUnmarshaler. It will unmarshal to a null Int if the input is a blank or not an integer. It will return an error if the input is not an integer, blank, or "null".

func (Int) ValueOrZero

func (i Int) ValueOrZero() int64

ValueOrZero returns the inner value if valid, otherwise zero.

type String

type String struct {
	sql.NullString
}

String is a nullable string. It supports SQL and JSON serialization. It will marshal to null if null. Blank string input will be considered null.

func NewString

func NewString(s string, valid bool) String

NewString creates a new String

func StringFrom

func StringFrom(s string) String

StringFrom creates a new String that will never be blank.

func StringFromPtr

func StringFromPtr(s *string) String

StringFromPtr creates a new String that be null if s is nil.

func (String) Equal

func (s String) Equal(other String) bool

Equal returns true if both strings have the same value or are both null.

func (String) IsZero

func (s String) IsZero() bool

IsZero returns true for null strings, for potential future omitempty support.

func (String) MarshalJSON

func (s String) MarshalJSON() ([]byte, error)

MarshalJSON implements json.Marshaler. It will encode null if this String is null.

func (String) MarshalText

func (s String) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler. It will encode a blank string when this String is null.

func (String) Ptr

func (s String) Ptr() *string

Ptr returns a pointer to this String's value, or a nil pointer if this String is null.

func (*String) SetValid

func (s *String) SetValid(v string)

SetValid changes this String's value and also sets it to be non-null.

func (*String) UnmarshalJSON

func (s *String) UnmarshalJSON(data []byte) error

UnmarshalJSON implements json.Unmarshaler. It supports string and null input. Blank string input does not produce a null String. It also supports unmarshalling a sql.NullString.

func (*String) UnmarshalText

func (s *String) UnmarshalText(text []byte) error

UnmarshalText implements encoding.TextUnmarshaler. It will unmarshal to a null String if the input is a blank string.

func (String) ValueOrZero

func (s String) ValueOrZero() string

ValueOrZero returns the inner value if valid, otherwise zero.

type Time

type Time struct {
	Time  time.Time
	Valid bool
}

Time is a nullable time.Time. It supports SQL and JSON serialization. It will marshal to null if null.

func NewTime

func NewTime(t time.Time, valid bool) Time

NewTime creates a new Time.

func TimeFrom

func TimeFrom(t time.Time) Time

TimeFrom creates a new Time that will always be valid.

func TimeFromPtr

func TimeFromPtr(t *time.Time) Time

TimeFromPtr creates a new Time that will be null if t is nil.

func (Time) Equal

func (t Time) Equal(other Time) bool

Equal returns true if both Time objects encode the same time or are both null. Two times can be equal even if they are in different locations. For example, 6:00 +0200 CEST and 4:00 UTC are Equal.

func (Time) ExactEqual

func (t Time) ExactEqual(other Time) bool

ExactEqual returns true if both Time objects are equal or both null. ExactEqual returns false for times that are in different locations or have a different monotonic clock reading.

func (Time) IsZero

func (t Time) IsZero() bool

IsZero returns true for invalid Times, hopefully for future omitempty support. A non-null Time with a zero value will not be considered zero.

func (Time) MarshalJSON

func (t Time) MarshalJSON() ([]byte, error)

MarshalJSON implements json.Marshaler. It will encode null if this time is null.

func (Time) MarshalText

func (t Time) MarshalText() ([]byte, error)

func (Time) Ptr

func (t Time) Ptr() *time.Time

Ptr returns a pointer to this Time's value, or a nil pointer if this Time is null.

func (*Time) Scan

func (t *Time) Scan(value interface{}) error

Scan implements the Scanner interface.

func (*Time) SetValid

func (t *Time) SetValid(v time.Time)

SetValid changes this Time's value and sets it to be non-null.

func (*Time) UnmarshalJSON

func (t *Time) UnmarshalJSON(data []byte) error

UnmarshalJSON implements json.Unmarshaler. It supports string, object (e.g. pq.NullTime and friends) and null input.

func (*Time) UnmarshalText

func (t *Time) UnmarshalText(text []byte) error

func (Time) Value

func (t Time) Value() (driver.Value, error)

Value implements the driver Valuer interface.

func (Time) ValueOrZero

func (t Time) ValueOrZero() time.Time

ValueOrZero returns the inner value if valid, otherwise zero.