Storing Golang JSON into Postgresql

Question

I want to store a certain struct into my database that has a JSON field within it.

type Comp struct {
    CompId               int64           `db:\"comp_id\" js         


        

Answer 1

I don't know how clean of a solution this is but I ended up making my own data type JSONRaw. The DB driver sees it as a []btye but it can still be treated like a json.RawMessage in the Go Code.

type JSONRaw json.RawMessage

func (j JSONRaw) Value() (driver.Value, error) {
    byteArr := []byte(j)

    return driver.Value(byteArr), nil
}

func (j *JSONRaw) Scan(src interface{}) error {
    asBytes, ok := src.([]byte)
    if !ok {
        return error(errors.New("Scan source was not []bytes"))
    }
    err := json.Unmarshal(asBytes, &j)
    if err != nil {
        return error(errors.New("Scan could not unmarshal to []string"))
    }

    return nil
}

func (m *JSONRaw) MarshalJSON() ([]byte, error) {
    return *m, nil
}

func (m *JSONRaw) UnmarshalJSON(data []byte) error {
    if m == nil {
        return errors.New("json.RawMessage: UnmarshalJSON on nil pointer")
    }
    *m = append((*m)[0:0], data...)
    return nil
}

This is copy paste reimplementation of MarshalJSON and UnmarshalJSON from the encoding/json library.

Answer 2

from the go documentation:

json.RawMessage is a raw encoded JSON object. It implements Marshaler and Unmarshaler and can be used to delay JSON decoding or precompute a JSON encoding.

if you log.Printf("%#", colors) in the example provided at package json json.RawMessage you can see that after unmarshalling the json object 'Point'-member isn't unmarshalled but left in []byte format until the color-format is fixed and 'Point' is unmarshalled explicitly.

Did you try something like unmarshal WeeklySchedule before putting it into the DB?

Answer 3

sqlx has a type JSONText in github.com/jmoiron/sqlx/types that will do what you need

doc for JSONText