diff --git a/gdb/orm/orm.go b/gdb/orm/orm.go
index d7bc6e1..aca135b 100644
--- a/gdb/orm/orm.go
+++ b/gdb/orm/orm.go
@@ -54,6 +54,29 @@ type ConnectionConfig struct {
 	DatabaseValidations bool
 }
 
+type DbOption struct {
+	Type    string
+	Dsn     string
+	MaxIdle int
+	MaxOpen int
+}
+
+func NewDb(opt DbOption) (*sql.DB, error) {
+	db, err := sql.Open(opt.Type, opt.Dsn)
+	if err != nil {
+		return nil, err
+	}
+	if opt.Type == "sqlite3" {
+		if opt.Dsn == ":memory:" {
+			db.SetMaxOpenConns(1)
+		}
+	} else {
+		db.SetMaxIdleConns(opt.MaxIdle)
+		db.SetMaxOpenConns(opt.MaxOpen)
+	}
+	return db, nil
+}
+
 // SetupConnections declares a new connections for ORM.
 func SetupConnections(configs ...ConnectionConfig) error {
 
diff --git a/go.mod b/go.mod
index 15a9383..bab2421 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module git.hexq.cn/tiglog/golib
 go 1.20
 
 require (
+	github.com/DATA-DOG/go-sqlmock v1.5.0
 	github.com/casbin/casbin/v2 v2.70.0
 	github.com/gin-gonic/gin v1.9.1
 	github.com/go-redis/redis/v8 v8.11.5
@@ -19,6 +20,7 @@ require (
 	go.mongodb.org/mongo-driver v1.11.7
 	go.uber.org/zap v1.25.0
 	golang.org/x/crypto v0.10.0
+	golang.org/x/sys v0.9.0
 	gopkg.in/natefinch/lumberjack.v2 v2.2.1
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -65,7 +67,6 @@ require (
 	golang.org/x/arch v0.3.0 // indirect
 	golang.org/x/net v0.10.0 // indirect
 	golang.org/x/sync v0.0.0-20210220032951-036812b2e83c // indirect
-	golang.org/x/sys v0.9.0 // indirect
 	golang.org/x/text v0.10.0 // indirect
 	golang.org/x/time v0.0.0-20190308202827-9d24e82272b4 // indirect
 	google.golang.org/protobuf v1.30.0 // indirect
diff --git a/go.sum b/go.sum
index 1d220e3..4a62c8d 100644
--- a/go.sum
+++ b/go.sum
@@ -1,4 +1,6 @@
 git.sr.ht/~nelsam/hel v0.4.3 h1:9W0zz8zv8CZhFsp8r9Wq6c8gFemBdtMurjZU/JKfvfM=
+github.com/DATA-DOG/go-sqlmock v1.5.0 h1:Shsta01QNfFxHCfpW6YH2STWB0MudeXXEWMr20OEh60=
+github.com/DATA-DOG/go-sqlmock v1.5.0/go.mod h1:f/Ixk793poVmq4qj/V1dPUg2JEAKC73Q5eFN3EC/SaM=
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible h1:1G1pk05UrOh0NlF1oeaaix1x8XzrfjIDK47TY0Zehcw=
 github.com/Knetic/govaluate v3.0.1-0.20171022003610-9aa49832a739+incompatible/go.mod h1:r7JcOSlj0wfOMncg0iLm8Leh48TZaKVeNIfJntJ2wa0=
 github.com/benbjohnson/clock v1.3.0 h1:ip6w0uFQkncKQ979AypyG0ER7mqUSBdKLOgAle/AT8A=