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https://github.com/guregu/null
reasonable handling of nullable values
https://github.com/guregu/null
go json sql
Last synced: 3 days ago
JSON representation
reasonable handling of nullable values
- Host: GitHub
- URL: https://github.com/guregu/null
- Owner: guregu
- License: bsd-2-clause
- Created: 2014-08-28T15:10:56.000Z (over 10 years ago)
- Default Branch: main
- Last Pushed: 2024-08-19T13:59:32.000Z (4 months ago)
- Last Synced: 2024-10-29T14:38:20.131Z (about 1 month ago)
- Topics: go, json, sql
- Language: Go
- Homepage:
- Size: 165 KB
- Stars: 1,855
- Watchers: 23
- Forks: 238
- Open Issues: 8
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Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
- go-awesome - guregu/null - "null" processing package for SQL/JSON that provides alternative types (Open source library / Development Aid Package)
- awesome-golang-repositories - null
- awesome - null - reasonable handling of nullable values (Go)
README
## null [](https://godoc.org/github.com/guregu/null/v5)
`import "github.com/guregu/null/v5"`
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.
#### Interfaces
- All types implement `sql.Scanner` and `driver.Valuer`, so you can use this library in place of `sql.NullXXX`.
- All types also implement `json.Marshaler` and `json.Unmarshaler`, so you can marshal them to their native JSON representation.
- All non-generic types implement `encoding.TextMarshaler`, `encoding.TextUnmarshaler`. A null object's `MarshalText` will return a blank string.
## null package
`import "github.com/guregu/null/v5"`
#### null.String
Nullable string.
Marshals to JSON null if SQL source data is null. Zero (blank) input will not produce a null String.
#### null.Int, null.Int32, null.Int16, null.Byte
Nullable int64/int32/int16/byte.
Marshals to JSON null if SQL source data is null. Zero input will not produce a null Int.
#### null.Float
Nullable float64.
Marshals to JSON null if SQL source data is null. Zero input will not produce a null Float.
#### null.Bool
Nullable bool.
Marshals to JSON null if SQL source data is null. False input will not produce a null Bool.
#### null.Time
Marshals to JSON null if SQL source data is null. Zero input will not produce a null Time.
#### null.Value
Generic nullable value.
Will marshal to JSON null if SQL source data is null. Does not implement `encoding.TextMarshaler`.
## zero package
`import "github.com/guregu/null/v5/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.
#### zero.Int, zero.Int32, zero.Int16, zero.Byte
Nullable int64/int32/int16/byte.
Will marshal to 0 if null. 0 produces a null Int. Null values and zero values are considered equivalent.
#### zero.Float
Nullable float64.
Will marshal to 0.0 if null. 0.0 produces a null Float. Null values and zero values are considered equivalent.
#### zero.Bool
Nullable bool.
Will marshal to false if null. `false` produces a null Float. Null values and zero values are considered equivalent.
#### zero.Time
Nullable time.
Will marshal to the zero time if null. Uses `time.Time`'s marshaler.
#### zero.Value[`T`]
Generic nullable value.
Will marshal to zero value if null. `T` is required to be a comparable type. Does not implement `encoding.TextMarshaler`.
## About
### Q&A
#### Can you add support for other types?
This package is intentionally limited in scope. It will only support the types that [`driver.Value`](https://godoc.org/database/sql/driver#Value) supports. Feel free to fork this and add more types if you want.
#### Can you add a feature that ____?
This package isn't intended to be a catch-all data-wrangling package. It is essentially finished. If you have an idea for a new feature, feel free to open an issue to talk about it or fork this package, but don't expect this to do everything.
### Package history
#### v5
- Now a Go module under the path `github.com/guregu/null/v5`
- Added missing types from `database/sql`: `Int32, Int16, Byte`
- Added generic `Value[T]` embedding `sql.Null[T]`
#### v4
- Available at `gopkg.in/guregu/null.v4`
- Unmarshaling from JSON `sql.NullXXX` JSON objects (e.g. `{"Int64": 123, "Valid": true}`) is no longer supported. It's unlikely many people used this, but if you need it, use v3.
### 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](https://github.com/golang/go/issues/11939).
### License
BSD