sql：列索引 5 上的扫描错误，名称“todos”：不支持扫描，存储驱动程序。值类型 []uint8 到类型 *[]datatypes.JSON golang gorm

Question

This is the model:

type Board struct {
    Id     uint `gorm:"primaryKey;autoIncrement;unique" json:"id"`
    Owner  uint `json:"owner"`
    Name string `json:"name"`
    Contributors []int `gorm:"type:jsonb" json:"contributors"`
    GeneratedLink string `gorm:"default:''" json:"generated_link"`
    Todos []datatypes.JSON `gorm:"type:jsonb" json:"todos"`
}

type TodoStructure struct {
    Id string `json:"id"`
    Text string `json:"text"`
    Completed bool `json:"completed"`
    Important bool `json:"important"`
}

This is how i create the board:

board := models.Board{
    Owner:         20,
    Name:          "text",
    GeneratedLink: "",
    Todos: []datatypes.JSON{datatypes.JSON("[]")},
}

database.DB.Create(&board)

This is how column looks after creating board:

so todos is just an empty array. And this is how i am creating todo:

func createTodo(c *gin.Context) {
    var board models.board
    database.DB.Where("id = ?", 1).First(&board)
    id := uuid.NewV4().String()
    todoStruct := models.TodoStructure{
        Id:        id,
        Text:      "text",
        Completed: false,
        Important: false,
    }

    jsonData, _ := json.Marshal(todoStruct)
    board.Todos = append(board.Todos, jsonData)
    fmt.Println(board.Todos) //exactly what i need [{"id":"e7ee015ab54c48388aa2413428f76f50","text":"text","completed":false,"important":false}]
    database.DB.Save(&board)
    c.JSON(http.StatusCreated, gin.H{"message": "success"})
}

but i got the error:

sql: Scan error on column index 5, name "todos": unsupported Scan, storing driver.Value type []uint8 into type *[]datatypes.JSON

and in column todo value saves like this:

just json object, but i need to save like this:

[{"id":"e7ee015ab54c48388aa2413428f76f50","text":"text","completed":false,"important":false}]

Please any ideas, any options, i tried to find the solution in the google but not found right solution.

PS using gorm and postgresql

Answer 1

I think you use the incorrect data type. Can you try this line?

    Todos []byte `gorm:"type:jsonb" json:"todos"`