golang使用Gorm查询数据库并在http响应中返回json

我是Go新手，正在使用Gorm查询我的postgres数据库，但无法以字典格式返回我的数据，其中pokemon的类型作为该类型的所有口袋妖怪的数组golang使用Gorm查询数据库并在http响应中返回json

JSON：不能解组对象进式的围棋值[] models.Pokemon

这里是我的代码：

type Pokemon struct { 
    Name string `db:"name"` 
    Type string `db:"type"` 
} 

pokemonTypes := [6]string{ 
    "fire", 
    "electric", 
    "water", 
    "grass", 
} 

var retData struct { 
    Poke []Pokemon 
} 

m := make(map[string][]Pokemon) 

for _, t := range pokemonTypes { 
    pokemon := DB.Where(&Pokemon{Type: t}).Find(&retData.Poke) 
    p, _ := json.Marshal(pokemon) 
    err = json.Unmarshal(p, &retData.Poke) // getting error here 
    if err != nil { 
     fmt.Println(err) 
    } 
    m[category] = retData.Poke 
} 

data, _ := json.Marshal(m) 
w.Write(data) // http repsonse 

我有这个在我的数据库

name  | type 
---------------------- 
pikachu | electric 
charmander | fire 
blaziken | fire 
venusaur | grass 
treeko  | grass 
squirtle | water 

我想在这个JSON格式

{ 
    “electric”: [ 
    {"name": "pikachu", "type": "electric"}, 
    ], 
    "fire": [ 
    {"name": "charmander", "type": "fire"}, 
    {"name": "blaziken", "type": "fire"} 
    ], 
    "grass": [ 
    {"name": "venusaur", "type": "grass"}, 
    {"name": "treeko", "type": "grass"}, 
    ], 
    "water": [ 
    {"name": "squirtle", "type": "water"}, 
    ] 
}