Function which returns list of struct from gorm database returning nil?

Question

I'm trying to make a function that will output all of the contents from a table as a slice of the struct the table is.

func FetchAll(parameter interface{}) []interface{} {
    var model interface{}

    var resultArray []interface{}

    db := common.GetDB()
    rows, err := db.Model(parameter).Where(parameter).Rows()
    if err != nil {
        fmt.Print(err.Error())
        return nil
    }
    for rows.Next() {
        db.ScanRows(rows, &model)
        resultArray = append(resultArray, model)
    }
    fmt.Println(resultArray)
    return resultArray
}

Usage:

c.JSON(200, FetchAll(&ProductImage{ProductID: productID}))

But the output is the following:

[<nil>,<nil>,<nil>]

Why is it?

Answer 1

the type of model can't be interface{}

you can use var model = map[string]interface{}{}

Easier to write：

func FetchAll(parameter interface{}) []map[string]interface{} {
    var resultArray []map[string]interface{}

    db := common.GetDB()
    err := db.Model(parameter).Where(parameter).Find(&resultArray).Error
    if err != nil {
        fmt.Print(err)
        return nil
    }
    fmt.Println(resultArray)
    return resultArray
}