我正在嘗試使用Gin和Gorm設置REST API。以下是我的：main.gopackage mainimport (    "app/config"    "app/service"    "github.com/gin-gonic/gin")func main() {    r := gin.Default()    // Connect to database    config.ConnectDatabase()    r.GET("/books", service.FindBooks)    // Run the server    r.Run()}在我的，我試圖像這樣連接到DBconfig/setup.gopackage configimport (    "github.com/jinzhu/gorm"    _ "github.com/jinzhu/gorm/dialects/mysql")var DB *gorm.DB// ConnectDatabase : Setup connection to databasefunc ConnectDatabase() {    database, err := gorm.Open("mysql", "root:password@tcp(127.0.0.1:3306)/test_db")    database.SingularTable(true)    if err != nil {        panic("Failed to connect to database!")    }    DB = database}在我的中，我有以下邏輯：service/book.gopackage serviceimport (    "errors"    "app/config"    "app/model"    "fmt"    "net/http"    "github.com/gin-gonic/gin")// FindBooks : Get all booksfunc FindBooks(c *gin.Context) {    c.JSON(http.StatusOK, gin.H{"data": FindAllBooks()})}// FindAllBooks : Fetch all book from DBfunc FindAllBooks() []model.Book {    var book []model.Book    config.DB.Find(&book)    for i := 0; i < len(book); i++ {        fmt.Println(book[i])    }    return book}而我的定義如下：model/Book.gopackage modeltype Book struct {    id        int64  `json:"id" gorm:"primary_key"`    label     string `json:"label" gorm:"type:varchar(255)"`}當我使用 運行應用程序時，以下是我可以看到的日志：go run main.go[GIN-debug] [WARNING] Creating an Engine instance with the Logger and Recovery middleware already attached.[GIN-debug] [WARNING] Running in "debug" mode. Switch to "release" mode in production. - using env:   export GIN_MODE=release - using code:  gin.SetMode(gin.ReleaseMode)[GIN-debug] GET    /books                    --> feedconsumer/service.FindBooks (3 handlers)[GIN-debug] Environment variable PORT is undefined. Using port :8080 by default[GIN-debug] Listening and serving HTTP on :8080{0   }[GIN] 2021/03/09 - 12:43:43 | 200 |    2.313864ms |             ::1 | GET      "/books"基本上，這意味著對象實際上沒有被獲取。我在這里錯過了什么？{0   }