fix: diff schema update assign value (#6096)

callbacks/update.go

@@ -245,11 +245,13 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 		}
 	default:
 		updatingSchema := stmt.Schema
+		var isDiffSchema bool
 		if !updatingValue.CanAddr() || stmt.Dest != stmt.Model {
 			// different schema
 			updatingStmt := &gorm.Statement{DB: stmt.DB}
 			if err := updatingStmt.Parse(stmt.Dest); err == nil {
 				updatingSchema = updatingStmt.Schema
+				isDiffSchema = true
 			}
 		}
 
@@ -276,7 +278,13 @@ func ConvertToAssignments(stmt *gorm.Statement) (set clause.Set) {
 
 							if (ok || !isZero) && field.Updatable {
 								set = append(set, clause.Assignment{Column: clause.Column{Name: field.DBName}, Value: value})
-								assignValue(field, value)
+								assignField := field
+								if isDiffSchema {
+									if originField := stmt.Schema.LookUpField(dbName); originField != nil {
+										assignField = originField
+									}
+								}
+								assignValue(assignField, value)
 							}
 						}
 					} else {

tests/update_test.go

@@ -773,3 +773,16 @@ func TestUpdateReturning(t *testing.T) {
 		t.Errorf("failed to return updated age column")
 	}
 }
+
+func TestUpdateWithDiffSchema(t *testing.T) {
+	user := GetUser("update-diff-schema-1", Config{})
+	DB.Create(&user)
+
+	type UserTemp struct {
+		Name string
+	}
+
+	err := DB.Model(&user).Updates(&UserTemp{Name: "update-diff-schema-2"}).Error
+	AssertEqual(t, err, nil)
+	AssertEqual(t, "update-diff-schema-2", user.Name)
+}