2nd

basic.go

@@ -40,21 +40,6 @@ func BasicUsage() {
 	fmt.Println("migrate success")
 }
 
-var DB *gorm.DB
-
-func init() {
-	// 定义DSN
-	const dsn = "root:secret@tcp(127.0.0.1:3306)/gormExample?charset=utf8mb4&parseTime=True&loc=Local"
-
-	// 连接服务器（池）
-	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{})
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	DB = db
-}
-
 func Create() {
 	// 构建Article类型数据
 	article := &Article{
@@ -123,3 +108,25 @@ func Delete() {
 	// print
 	fmt.Println("article was deleted")
 }
+
+func Debug() {
+	// insert
+	article := &Article{
+		Subject:     "GORM 的 CRUD 基础操作",
+		PublishTime: time.Now(),
+	}
+	if err := DB.
+		Debug().
+		Create(article).Error; err != nil {
+		log.Fatal(err)
+	}
+
+	// select
+	if err := DB.Debug().First(article, article.ID).Error; err != nil {
+		log.Fatal(err)
+	}
+}
+
+func Log() {
+	Create()
+}

basic_test.go

@@ -21,3 +21,11 @@ func TestUpdate(t *testing.T) {
 func TestDelete(t *testing.T) {
 	Delete()
 }
+
+func TestDebug(t *testing.T) {
+	Debug()
+}
+
+func TestLog(t *testing.T) {
+	Log()
+}

init.go

@@ -0,0 +1,69 @@
+package gormExample
+
+import (
+	"gorm.io/driver/mysql"
+	"gorm.io/gorm"
+	"gorm.io/gorm/logger"
+	"gorm.io/gorm/schema"
+	"io"
+	"log"
+	"os"
+	"time"
+)
+
+var DB *gorm.DB
+
+// 配置全局日志级别
+//func init() {
+//	// 定义DSN
+//	const dsn = "root:secret@tcp(127.0.0.1:3306)/gormExample?charset=utf8mb4&parseTime=True&loc=Local"
+//
+//	// 连接服务器（池）
+//	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{
+//		// 设置Info级别的默认日志
+//		Logger: logger.Default.LogMode(logger.Info),
+//	})
+//	if err != nil {
+//		log.Fatal(err)
+//	}
+//
+//	DB = db
+//}
+
+// 自定义日志
+var logWriter io.Writer
+
+func init() {
+	// 定义DSN
+	const dsn = "root:secret@tcp(127.0.0.1:3306)/gormExample?charset=utf8mb4&parseTime=True&loc=Local"
+	// 初始化logWriter
+	logWriter, _ = os.OpenFile("./sql.log", os.O_CREATE|os.O_APPEND, 0644)
+	customLogger := logger.New(log.New(logWriter, "\n", log.LstdFlags),
+		logger.Config{
+			// 慢查询阈值 200ms
+			SlowThreshold: 200 * time.Millisecond,
+			// 日志级别
+			LogLevel: logger.Info,
+			// 是否忽略记录不存在的错误
+			IgnoreRecordNotFoundError: false,
+			// 不彩色化
+			Colorful: false,
+		})
+	// 连接服务器（池）
+	db, err := gorm.Open(mysql.Open(dsn), &gorm.Config{
+		// 设置为自定义的日志
+		Logger: customLogger,
+		// 设置默认的命名策略的选项
+		NamingStrategy: schema.NamingStrategy{
+			TablePrefix:   "msb_",
+			SingularTable: true,
+			NameReplacer:  nil,
+			NoLowerCase:   false,
+		},
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	DB = db
+}

model.go

@@ -0,0 +1,54 @@
+package gormExample
+
+import (
+	"fmt"
+	"gorm.io/gorm"
+	"log"
+	"time"
+)
+
+type Post struct{ gorm.Model }
+type Category struct{ gorm.Model }
+type PostCategory struct{ gorm.Model }
+type Box struct{ gorm.Model }
+
+func (Box) TableName() string {
+	return "my_box"
+}
+
+type TypeMap struct {
+	gorm.Model
+
+	FInt       int
+	FUInt      uint
+	FFloat32   float32
+	FFloat64   float64
+	FString    string
+	FTime      time.Time
+	FByteSlice []byte
+
+	FIntP     *int
+	FUIntP    *uint
+	FFloat32P *float32
+	FFloat64P *float64
+	FStringP  *string
+	FTimeP    *time.Time
+}
+
+func Migrate() {
+	if err := DB.Debug().AutoMigrate(&TypeMap{}, &Post{}, &Category{}, &PostCategory{}, &Box{}); err != nil {
+		log.Fatal(err)
+	}
+}
+
+func PointerDiff() {
+	// 模型的零值
+	typeMap := &TypeMap{}
+	fmt.Printf("%+v\n", typeMap)
+
+	fmt.Println("=================================")
+
+	// 查询数据NULL对应的值
+	DB.First(typeMap, 1)
+	fmt.Printf("%+v\n", typeMap)
+}

model_test.go

@@ -0,0 +1,11 @@
+package gormExample
+
+import "testing"
+
+func TestMigrate(t *testing.T) {
+	Migrate()
+}
+
+func TestPointerDiff(t *testing.T) {
+	PointerDiff()
+}