diff --git a/cmd/main.go b/cmd/main.go
index 66081b9..ef7396c 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -16,17 +16,34 @@ package main
 import (
 	_ "time/tzdata"
 
+	"github.com/spf13/cobra"
+
+	"github.com/opentreehole/backend/cmd/migrate"
 	"github.com/opentreehole/backend/cmd/wire"
 	_ "github.com/opentreehole/backend/internal/docs"
 )
 
+var rootCmd = &cobra.Command{
+	Use: "opentreehole_backend",
+	Run: func(cmd *cobra.Command, args []string) {
+		server, cleanup, err := wire.NewApp()
+		if err != nil {
+			panic(err)
+		}
+
+		defer cleanup()
+		server.Run()
+	},
+}
+
+func init() {
+	rootCmd.AddCommand(migrate.Cmd)
+}
+
 //go:generate wire gen ./wire
 func main() {
-	server, cleanup, err := wire.NewApp()
+	err := rootCmd.Execute()
 	if err != nil {
 		panic(err)
 	}
-
-	defer cleanup()
-	server.Run()
 }
diff --git a/cmd/migrate_danke_v3/main.go b/cmd/migrate/danke_v3.go
similarity index 95%
rename from cmd/migrate_danke_v3/main.go
rename to cmd/migrate/danke_v3.go
index d53f9b5..5dec2cb 100644
--- a/cmd/migrate_danke_v3/main.go
+++ b/cmd/migrate/danke_v3.go
@@ -1,7 +1,4 @@
-//! 迁移旧版本蛋壳到新版本
-//! `review`.`history` -> `review_history`
-
-package main
+package migrate
 
 import (
 	"time"
@@ -52,7 +49,7 @@ type ReviewOld struct {
 	Downvoters  []int               `json:"downvoters" gorm:"serializer:json"`
 }
 
-func main() {
+func DankeV3() {
 	conf := config.NewConfig()
 	logger, cancel := log.NewLogger(conf)
 	defer cancel()
@@ -62,8 +59,10 @@ func main() {
 		reviews []*ReviewOld
 		err     error
 	)
+	logger.Info("migrate danke v3")
 
 	err = db.Transaction(func(tx *gorm.DB) error {
+		logger.Info("migrate danke v3: get reviews")
 		err = db.Table("review").FindInBatches(&reviews, 1000, func(tx *gorm.DB, batch int) error {
 			// update History
 			var (
@@ -138,14 +137,14 @@ func main() {
 		}
 
 		// update course.review_count
-		err = db.Exec(`update course set review_count = (select count(*) from review where review.course_id = course.id) where true`).Error
+		err = tx.Exec(`update course set review_count = (select count(*) from review where review.course_id = course.id) where true`).Error
 		if err != nil {
 			return err
 		}
 
 		// update review.upvote_count and review.downvote_count
 		// extract review.rank_* from review.rank
-		err = db.Exec(`update review 
+		err = tx.Exec(`update review 
 set upvote_count = (select count(*) from review_vote where review_vote.review_id = review.id and review_vote.data = 1), 
     downvote_count = (select count(*) from review_vote where review_vote.review_id = review.id and review_vote.data = -1),
 	rank_overall = JSON_EXTRACT(review.rank, '$.overall'),
diff --git a/cmd/migrate/main.go b/cmd/migrate/main.go
new file mode 100644
index 0000000..d62e4a3
--- /dev/null
+++ b/cmd/migrate/main.go
@@ -0,0 +1,27 @@
+//! 迁移旧版本蛋壳到新版本
+//! `review`.`history` -> `review_history`
+
+package migrate
+
+import (
+	"fmt"
+
+	"github.com/spf13/cobra"
+)
+
+var Cmd = &cobra.Command{
+	Use: "migrate",
+	RunE: func(cmd *cobra.Command, args []string) error {
+		if len(args) == 0 {
+			return fmt.Errorf("no migration specified")
+		}
+
+		switch args[0] {
+		case "danke_v3":
+			DankeV3()
+		default:
+			return fmt.Errorf("unknown migration %s", args[0])
+		}
+		return nil
+	},
+}
diff --git a/data/data.go b/data/data.go
index ee88dcc..275336b 100644
--- a/data/data.go
+++ b/data/data.go
@@ -6,7 +6,6 @@ import (
 	"os"
 
 	"github.com/goccy/go-json"
-	"github.com/rs/zerolog/log"
 )
 
 //go:embed names.json
@@ -23,13 +22,11 @@ var NamesMapping map[string]string
 func init() {
 	NamesMappingData, err := os.ReadFile(`data/names_mapping.json`)
 	if err != nil {
-		log.Err(err).Msg("could not load names_mapping.json")
 		return
 	}
 
 	err = json.Unmarshal(NamesMappingData, &NamesMapping)
 	if err != nil {
-		log.Err(err).Msg("could not unmarshal names_mapping.json")
 		return
 	}
 }
diff --git a/go.mod b/go.mod
index b58e435..f93c49a 100644
--- a/go.mod
+++ b/go.mod
@@ -21,6 +21,7 @@ require (
 	github.com/jinzhu/copier v0.4.0
 	github.com/redis/go-redis/v9 v9.2.0
 	github.com/rs/zerolog v1.30.0
+	github.com/spf13/cobra v1.7.0
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.8.4
 	github.com/swaggo/swag v1.16.2
@@ -54,6 +55,7 @@ require (
 	github.com/golang/mock v1.6.0 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/google/uuid v1.3.1 // indirect
+	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a // indirect
 	github.com/jackc/pgx/v5 v5.3.1 // indirect
diff --git a/go.sum b/go.sum
index b8b7380..519e400 100644
--- a/go.sum
+++ b/go.sum
@@ -68,6 +68,7 @@ github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDk
 github.com/cncf/udpa/go v0.0.0-20191209042840-269d4d468f6f/go.mod h1:M8M6+tZqaGXZJjfX53e64911xZQV5JYwmTeXPW+k8Sc=
 github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
 github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d/go.mod h1:maD7wRr/U5Z6m/iR4s+kqSMx2CaBsrgA7czyZG/E6dU=
+github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/creack/pty v1.1.9/go.mod h1:oKZEueFk5CKHvIhNR5MUki03XCEU+Q6VDXinZuGJ33E=
 github.com/creasty/defaults v1.7.0 h1:eNdqZvc5B509z18lD8yc212CAqJNvfT1Jq6L8WowdBA=
 github.com/creasty/defaults v1.7.0/go.mod h1:iGzKe6pbEHnpMPtfDXZEr0NVxWnPTjb1bbDy08fPzYM=
@@ -206,6 +207,8 @@ github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ
 github.com/hetiansu5/urlquery v1.2.7 h1:jn0h+9pIRqUziSPnRdK/gJK8S5TCnk+HZZx5fRHf8K0=
 github.com/hetiansu5/urlquery v1.2.7/go.mod h1:wFpZdTHRdwt7mk0EM/DdZEWtEN4xf8HJoH/BLXm/PG0=
 github.com/ianlancetaylor/demangle v0.0.0-20181102032728-5e5cf60278f6/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
+github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
+github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/jackc/pgpassfile v1.0.0 h1:/6Hmqy13Ss2zCq62VdNG8tM1wchn8zjSGOBJ6icpsIM=
 github.com/jackc/pgpassfile v1.0.0/go.mod h1:CEx0iS5ambNFdcRtxPj5JhEz+xB6uRky5eyVu/W2HEg=
 github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a h1:bbPeKD0xmW/Y25WS6cokEszi5g+S0QxI/d45PkRi7Nk=
@@ -318,10 +321,13 @@ github.com/rs/xid v1.5.0/go.mod h1:trrq9SKmegXys3aeAKXMUTdJsYXVwGY3RLcfgqegfbg=
 github.com/rs/zerolog v1.30.0 h1:SymVODrcRsaRaSInD9yQtKbtWqwsfoPcRff/oRXLj4c=
 github.com/rs/zerolog v1.30.0/go.mod h1:/tk+P47gFdPXq4QYjvCmT5/Gsug2nagsFWBWhAiSi1w=
 github.com/russross/blackfriday/v2 v2.0.1/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
+github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
 github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
 github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
 github.com/sirupsen/logrus v1.4.2/go.mod h1:tLMulIdttU9McNUspp0xgXVQah82FyeX6MwdIuYE2rE=
 github.com/sirupsen/logrus v1.6.0/go.mod h1:7uNnSEd1DgxDLC74fIahvMZmmYsHGZGEOFrfsX/uA88=
+github.com/spf13/cobra v1.7.0 h1:hyqWnYt1ZQShIddO5kBpj3vu05/++x6tJ6dg8EC572I=
+github.com/spf13/cobra v1.7.0/go.mod h1:uLxZILRyS/50WlhOIKD7W6V5bgeIt+4sICxh6uRMrb0=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
diff --git a/internal/config/config.go b/internal/config/config.go
index c34b170..1c783c1 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -15,31 +15,31 @@ import (
 )
 
 type EnvConfig struct {
-	Mode string `env:"MODE" default:"dev" validate:"oneof=dev production test bench"`
+	Mode string `env:"MODE"`
 
-	LogLevel string `env:"LOG_LEVEL" default:"debug" validate:"oneof=debug info warn error dpanic panic fatal"`
+	LogLevel string `env:"LOG_LEVEL" `
 
-	Port int `env:"PORT" default:"8000"`
+	Port int `env:"PORT" `
 
-	DBType string `env:"DB_TYPE" default:"sqlite" validate:"oneof=mysql sqlite postgres memory"`
+	DBType string `env:"DB_TYPE"`
 
-	DBDSN string `env:"DB_DSN" default:"data/sqlite.db"`
+	DBDSN string `env:"DB_DSN"`
 
-	CacheType string `env:"CACHE_TYPE" default:"memory" validate:"oneof=redis memory"`
+	CacheType string `env:"CACHE_TYPE" `
 
-	CacheUrl string `env:"CACHE_URL" default:"redis:6379"`
+	CacheUrl string `env:"CACHE_URL" `
 
-	SearchEngineType string `env:"SEARCH_ENGINE_TYPE" default:"elasticsearch" validate:"oneof=elasticsearch meilisearch"`
+	SearchEngineType string `env:"SEARCH_ENGINE_TYPE" `
 
-	SearchEngineUrl string `env:"SEARCH_ENGINE_URL" default:"http://elasticsearch:9200"`
+	SearchEngineUrl string `env:"SEARCH_ENGINE_URL" `
 
-	ModulesAuth bool `env:"MODULES_AUTH" default:"false"`
+	ModulesAuth bool `env:"MODULES_AUTH" `
 
-	ModulesNotification bool `env:"MODULES_NOTIFICATION" default:"false"`
+	ModulesNotification bool `env:"MODULES_NOTIFICATION"`
 
-	ModulesTreehole bool `env:"MODULES_TREEHOLE" default:"false"`
+	ModulesTreehole bool `env:"MODULES_TREEHOLE"`
 
-	ModulesCurriculumBoard bool `env:"MODULES_CURRICULUM_BOARD" default:"false"`
+	ModulesCurriculumBoard bool `env:"MODULES_CURRICULUM_BOARD"`
 }
 
 type Config struct {
@@ -357,17 +357,55 @@ func (config *Config) WriteIntoFile(name string) {
 }
 
 func CopyEnvConfigToConfig(envConfig *EnvConfig, config *Config) {
-	config.Mode = envConfig.Mode
-	config.LogLevel = envConfig.LogLevel
-	config.Port = envConfig.Port
-	config.DB.Type = envConfig.DBType
-	config.DB.DSN = envConfig.DBDSN
-	config.Cache.Type = envConfig.CacheType
-	config.Cache.Url = envConfig.CacheUrl
-	config.SearchEngine.Type = envConfig.SearchEngineType
-	config.SearchEngine.Url = envConfig.SearchEngineUrl
-	config.Modules.Auth = envConfig.ModulesAuth
-	config.Modules.Notification = envConfig.ModulesNotification
-	config.Modules.Treehole = envConfig.ModulesTreehole
-	config.Modules.CurriculumBoard = envConfig.ModulesCurriculumBoard
+	if envConfig.Mode != "" {
+		config.Mode = envConfig.Mode
+	}
+
+	if envConfig.LogLevel != "" {
+		config.LogLevel = envConfig.LogLevel
+	}
+
+	if envConfig.Port != 0 {
+		config.Port = envConfig.Port
+	}
+
+	if envConfig.DBType != "" {
+		config.DB.Type = envConfig.DBType
+	}
+
+	if envConfig.DBDSN != "" {
+		config.DB.DSN = envConfig.DBDSN
+	}
+
+	if envConfig.CacheType != "" {
+		config.Cache.Type = envConfig.CacheType
+	}
+
+	if envConfig.CacheUrl != "" {
+		config.Cache.Url = envConfig.CacheUrl
+	}
+
+	if envConfig.SearchEngineType != "" {
+		config.SearchEngine.Type = envConfig.SearchEngineType
+	}
+
+	if envConfig.SearchEngineUrl != "" {
+		config.SearchEngine.Url = envConfig.SearchEngineUrl
+	}
+
+	if envConfig.ModulesAuth {
+		config.Modules.Auth = envConfig.ModulesAuth
+	}
+
+	if envConfig.ModulesNotification {
+		config.Modules.Notification = envConfig.ModulesNotification
+	}
+
+	if envConfig.ModulesTreehole {
+		config.Modules.Treehole = envConfig.ModulesTreehole
+	}
+
+	if envConfig.ModulesCurriculumBoard {
+		config.Modules.CurriculumBoard = envConfig.ModulesCurriculumBoard
+	}
 }