diff --git a/schema/relationship_test.go b/schema/relationship_test.go
index 5b37a784..b6d2f9b1 100644
--- a/schema/relationship_test.go
+++ b/schema/relationship_test.go
@@ -2,11 +2,6 @@ package schema
 
 import "testing"
 
-type BelongsTo struct {
-	ID   int
-	Name string
-}
-
 type HasOne struct {
 	ID         int
 	MyStructID uint
@@ -24,13 +19,94 @@ type Many2Many struct {
 }
 
 func TestBelongsToRel(t *testing.T) {
-	type MyStruct struct {
-		ID        int
-		Name      string
-		BelongsTo BelongsTo
+	type BelongsTo struct {
+		ID   int
+		Name string
 	}
 
-	Parse(&MyStruct{})
+	type MyStruct struct {
+		ID          int
+		Name        string
+		BelongsToID uint
+		BelongsTo   BelongsTo
+	}
+
+	schema := Parse(&MyStruct{})
+	compareFields(schema.Fields, []*Field{
+		{DBName: "id", Name: "ID", BindNames: []string{"ID"}, IsNormal: true, IsPrimaryKey: true},
+		{DBName: "name", Name: "Name", BindNames: []string{"Name"}, IsNormal: true},
+		{DBName: "belongs_to_id", Name: "BelongsToID", BindNames: []string{"BelongsToID"}, IsNormal: true, IsForeignKey: true},
+		{DBName: "belongs_to", Name: "BelongsTo", BindNames: []string{"BelongsTo"}, Relationship: &Relationship{Kind: "belongs_to", ForeignKey: []string{"belongs_to_id"}, AssociationForeignKey: []string{"id"}}},
+	}, t)
+
+	type MyStruct2 struct {
+		ID           int `gorm:"column:my_id"`
+		Name         string
+		BelongsToKey uint
+		BelongsTo    BelongsTo `gorm:"foreignkey:BelongsToKey"`
+	}
+
+	schema2 := Parse(&MyStruct2{})
+	compareFields(schema2.Fields, []*Field{
+		{DBName: "my_id", Name: "ID", BindNames: []string{"ID"}, IsNormal: true, IsPrimaryKey: true, TagSettings: map[string]string{"COLUMN": "my_id"}},
+		{DBName: "name", Name: "Name", BindNames: []string{"Name"}, IsNormal: true},
+		{DBName: "belongs_to_key", Name: "BelongsToKey", BindNames: []string{"BelongsToKey"}, IsNormal: true, IsForeignKey: true},
+		{DBName: "belongs_to", Name: "BelongsTo", BindNames: []string{"BelongsTo"}, Relationship: &Relationship{Kind: "belongs_to", ForeignKey: []string{"belongs_to_key"}, AssociationForeignKey: []string{"id"}}, TagSettings: map[string]string{"FOREIGNKEY": "BelongsToKey"}},
+	}, t)
+
+	type BelongsTo3 struct {
+		ID   int `gorm:"column:my_id"`
+		Name string
+	}
+
+	type MyStruct3 struct {
+		ID           int
+		Name         string
+		BelongsToKey uint
+		BelongsTo    BelongsTo3 `gorm:"foreignkey:BelongsToKey"`
+	}
+
+	schema3 := Parse(&MyStruct3{})
+	compareFields(schema3.Fields, []*Field{
+		{DBName: "id", Name: "ID", BindNames: []string{"ID"}, IsNormal: true, IsPrimaryKey: true},
+		{DBName: "name", Name: "Name", BindNames: []string{"Name"}, IsNormal: true},
+		{DBName: "belongs_to_key", Name: "BelongsToKey", BindNames: []string{"BelongsToKey"}, IsNormal: true, IsForeignKey: true},
+		{DBName: "belongs_to", Name: "BelongsTo", BindNames: []string{"BelongsTo"}, Relationship: &Relationship{Kind: "belongs_to", ForeignKey: []string{"belongs_to_key"}, AssociationForeignKey: []string{"my_id"}}, TagSettings: map[string]string{"FOREIGNKEY": "BelongsToKey"}},
+	}, t)
+}
+
+func TestSelfReferenceBelongsToRel(t *testing.T) {
+	type MyStruct struct {
+		ID          int
+		Name        string
+		BelongsToID int
+		BelongsTo   *MyStruct
+	}
+
+	// user1 belongs to user2, when creating, will create user2 first
+	schema := Parse(&MyStruct{})
+	compareFields(schema.Fields, []*Field{
+		{DBName: "id", Name: "ID", BindNames: []string{"ID"}, IsNormal: true, IsPrimaryKey: true},
+		{DBName: "name", Name: "Name", BindNames: []string{"Name"}, IsNormal: true},
+		{DBName: "belongs_to_id", Name: "BelongsToID", BindNames: []string{"BelongsToID"}, IsNormal: true, IsForeignKey: true},
+		{DBName: "belongs_to", Name: "BelongsTo", BindNames: []string{"BelongsTo"}, Relationship: &Relationship{Kind: "belongs_to", ForeignKey: []string{"belongs_to_id"}, AssociationForeignKey: []string{"id"}}},
+	}, t)
+
+	type MyStruct2 struct {
+		ID           int
+		Name         string
+		BelongsToKey int
+		BelongsTo    *MyStruct2 `gorm:"rel:belongs_to;foreignkey:BelongsToKey"`
+	}
+
+	// user1 belongs to user2, when creating, will create user2 first
+	schema2 := Parse(&MyStruct2{})
+	compareFields(schema2.Fields, []*Field{
+		{DBName: "id", Name: "ID", BindNames: []string{"ID"}, IsNormal: true, IsPrimaryKey: true},
+		{DBName: "name", Name: "Name", BindNames: []string{"Name"}, IsNormal: true},
+		{DBName: "belongs_to_key", Name: "BelongsToKey", BindNames: []string{"BelongsToKey"}, IsNormal: true, IsForeignKey: true},
+		{DBName: "belongs_to", Name: "BelongsTo", BindNames: []string{"BelongsTo"}, Relationship: &Relationship{Kind: "belongs_to", ForeignKey: []string{"belongs_to_key"}, AssociationForeignKey: []string{"id"}}, TagSettings: map[string]string{"FOREIGNKEY": "BelongsToKey"}},
+	}, t)
 }
 
 func TestHasOneRel(t *testing.T) {
@@ -43,6 +119,46 @@ func TestHasOneRel(t *testing.T) {
 	Parse(&MyStruct{})
 }
 
+func TestSelfReferenceHasOneRel(t *testing.T) {
+	type MyStruct struct {
+		ID          int
+		Name        string
+		BelongsToID int
+		BelongsTo   *MyStruct
+	}
+
+	// user1 belongs to user2, when creating, will create user2 first
+	schema := Parse(&MyStruct{})
+	compareFields(schema.Fields, []*Field{
+		{DBName: "id", Name: "ID", BindNames: []string{"ID"}, IsNormal: true, IsPrimaryKey: true},
+		{DBName: "name", Name: "Name", BindNames: []string{"Name"}, IsNormal: true},
+		{DBName: "belongs_to_id", Name: "BelongsToID", BindNames: []string{"BelongsToID"}, IsNormal: true, IsForeignKey: true},
+		{DBName: "belongs_to", Name: "BelongsTo", BindNames: []string{"BelongsTo"}, Relationship: &Relationship{Kind: "belongs_to", ForeignKey: []string{"belongs_to_id"}, AssociationForeignKey: []string{"id"}}},
+	}, t)
+}
+
+func TestPolymorphicHasOneRel(t *testing.T) {
+	type HasOne struct {
+		ID        int
+		Name      string
+		OwnerType string
+		OwnerID   string
+	}
+
+	type MyStruct struct {
+		ID     int
+		Name   string
+		HasOne HasOne `gorm:"polymorphic:Owner"`
+	}
+
+	schema := Parse(&MyStruct{})
+	compareFields(schema.Fields, []*Field{
+		{DBName: "id", Name: "ID", BindNames: []string{"ID"}, IsNormal: true, IsPrimaryKey: true},
+		{DBName: "name", Name: "Name", BindNames: []string{"Name"}, IsNormal: true},
+		{DBName: "has_one", Name: "HasOne", BindNames: []string{"HasOne"}, Relationship: &Relationship{Kind: "has_one", PolymorphicType: "OwnerType", PolymorphicDBName: "owner_type", PolymorphicValue: "my_struct", ForeignKey: []string{"owner_id"}, AssociationForeignKey: []string{"id"}}, TagSettings: map[string]string{"POLYMORPHIC": "Owner"}},
+	}, t)
+}
+
 func TestHasManyRel(t *testing.T) {
 	type MyStruct struct {
 		ID      int
@@ -62,4 +178,3 @@ func TestManyToManyRel(t *testing.T) {
 
 	Parse(&MyStruct{})
 }
-
diff --git a/schema/schema.go b/schema/schema.go
index 1420d997..c01b67cc 100644
--- a/schema/schema.go
+++ b/schema/schema.go
@@ -5,9 +5,13 @@ import (
 	"go/ast"
 	"reflect"
 	"sort"
+	"strings"
+	"sync"
 	"time"
 )
 
+var schemaMap = sync.Map{}
+
 // Schema model schema definition
 type Schema struct {
 	ModelType     reflect.Type
@@ -48,6 +52,10 @@ func Parse(dest interface{}) *Schema {
 		return nil
 	}
 
+	if m, ok := schemaMap.Load(reflectType); ok {
+		return m.(*Schema)
+	}
+
 	schema.ModelType = reflectType
 	onConflictFields := map[string]int{}
 
@@ -221,12 +229,16 @@ func Parse(dest interface{}) *Schema {
 	}
 
 	if len(schema.PrimaryFields) == 0 {
-		if field := getSchemaField("id", schema.Fields); field != nil {
-			field.IsPrimaryKey = true
-			schema.PrimaryFields = append(schema.PrimaryFields, field)
+		for _, field := range schema.Fields {
+			if strings.ToUpper(field.Name) == "ID" || field.DBName == "id" {
+				field.IsPrimaryKey = true
+				schema.PrimaryFields = append(schema.PrimaryFields, field)
+				break
+			}
 		}
 	}
 
+	schemaMap.Store(reflectType, &schema)
 	return &schema
 }
 
diff --git a/schema/schema_test.go b/schema/schema_test.go
index a2f1d24c..405a0070 100644
--- a/schema/schema_test.go
+++ b/schema/schema_test.go
@@ -293,5 +293,9 @@ func fieldEqual(got, expected *Field) error {
 	if expected.HasDefaultValue != got.HasDefaultValue {
 		return fmt.Errorf("field HasDefaultValue should be %v, got %v", expected.HasDefaultValue, got.HasDefaultValue)
 	}
+
+	if !reflect.DeepEqual(expected.Relationship, got.Relationship) {
+		return fmt.Errorf("field Relationship should be %#v, got %#v", expected.Relationship, got.Relationship)
+	}
 	return nil
 }