Support Variable Relation

schema/relationship.go

@@ -416,6 +416,10 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 		}
 	} else {
 		var primaryFields []*Field
+		var primarySchemaName = primarySchema.Name
+		if primarySchemaName == "" {
+			primarySchemaName = relation.FieldSchema.Name
+		}
 
 		if len(relation.primaryKeys) > 0 {
 			for _, primaryKey := range relation.primaryKeys {
@@ -428,7 +432,7 @@ func (schema *Schema) guessRelation(relation *Relationship, field *Field, cgl gu
 		}
 
 		for _, primaryField := range primaryFields {
-			lookUpName := primarySchema.Name + primaryField.Name
+			lookUpName := primarySchemaName + primaryField.Name
 			if gl == guessBelongs {
 				lookUpName = field.Name + primaryField.Name
 			}

schema/relationship_test.go

@@ -491,6 +491,26 @@ func TestEmbeddedRelation(t *testing.T) {
 	}
 }
 
+func TestVariableRelation(t *testing.T) {
+	var result struct {
+		User
+	}
+
+	checkStructRelation(t, &result, Relation{
+		Name: "Account", Type: schema.HasOne, Schema: "", FieldSchema: "Account",
+		References: []Reference{
+			{"ID", "", "UserID", "Account", "", true},
+		},
+	})
+
+	checkStructRelation(t, &result, Relation{
+		Name: "Company", Type: schema.BelongsTo, Schema: "", FieldSchema: "Company",
+		References: []Reference{
+			{"ID", "Company", "CompanyID", "", "", false},
+		},
+	})
+}
+
 func TestSameForeignKey(t *testing.T) {
 	type UserAux struct {
 		gorm.Model