From 628a0ae707f230c67bca2e632fb302037c707705 Mon Sep 17 00:00:00 2001
From: Jinzhu <wosmvp@gmail.com>
Date: Mon, 15 Feb 2021 09:10:51 +0800
Subject: [PATCH] Fix foreign key & reference with same name, close #4081

---
 schema/relationship.go      | 20 ++++++++++++++++----
 schema/relationship_test.go | 24 ++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/schema/relationship.go b/schema/relationship.go
index 0eaace89..1aa2d11a 100644
--- a/schema/relationship.go
+++ b/schema/relationship.go
@@ -81,7 +81,7 @@ func (schema *Schema) parseRelation(field *Field) *Relationship {
 	} else {
 		switch field.IndirectFieldType.Kind() {
 		case reflect.Struct:
-			schema.guessRelation(relation, field, guessBelongs)
+			schema.guessRelation(relation, field, guessGuess)
 		case reflect.Slice:
 			schema.guessRelation(relation, field, guessHas)
 		default:
@@ -341,20 +341,32 @@ func (schema *Schema) buildMany2ManyRelation(relation *Relationship, field *Fiel
 type guessLevel int
 
 const (
-	guessBelongs guessLevel = iota
+	guessGuess guessLevel = iota
+	guessBelongs
 	guessEmbeddedBelongs
 	guessHas
 	guessEmbeddedHas
 )
 
-func (schema *Schema) guessRelation(relation *Relationship, field *Field, gl guessLevel) {
+func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl guessLevel) {
 	var (
 		primaryFields, foreignFields []*Field
 		primarySchema, foreignSchema = schema, relation.FieldSchema
+		gl                           = cgl
 	)
 
+	if gl == guessGuess {
+		if field.Schema == relation.FieldSchema {
+			gl = guessBelongs
+		} else {
+			gl = guessHas
+		}
+	}
+
 	reguessOrErr := func() {
-		switch gl {
+		switch cgl {
+		case guessGuess:
+			schema.guessRelation(relation, field, guessBelongs)
 		case guessBelongs:
 			schema.guessRelation(relation, field, guessEmbeddedBelongs)
 		case guessEmbeddedBelongs:
diff --git a/schema/relationship_test.go b/schema/relationship_test.go
index 64d0c2a7..a34777b7 100644
--- a/schema/relationship_test.go
+++ b/schema/relationship_test.go
@@ -433,3 +433,27 @@ func TestEmbeddedRelation(t *testing.T) {
 		t.Fatalf("expects created by relations, but not found")
 	}
 }
+
+func TestSameForeignKey(t *testing.T) {
+	type UserAux struct {
+		gorm.Model
+		Aux  string
+		UUID string
+	}
+
+	type User struct {
+		gorm.Model
+		Name string
+		UUID string
+		Aux  *UserAux `gorm:"foreignkey:UUID;references:UUID"`
+	}
+
+	checkStructRelation(t, &User{},
+		Relation{
+			Name: "Aux", Type: schema.HasOne, Schema: "User", FieldSchema: "UserAux",
+			References: []Reference{
+				{"UUID", "User", "UUID", "UserAux", "", true},
+			},
+		},
+	)
+}