fixed: queryCallback error if params to Find is created by reflection

callback_query.go

@@ -26,8 +26,13 @@ func queryCallback(scope *Scope) {
 
 	defer scope.trace(scope.db.nowFunc())
 
+	if reflect.ValueOf(scope.Value).Kind() != reflect.Ptr {
+		panic("results argument must be a slice address")
+	}
+
 	var (
 		isSlice, isPtr bool
+		slicev         reflect.Value
 		resultType     reflect.Type
 		results        = scope.IndirectValue()
 	)
@@ -42,11 +47,18 @@ func queryCallback(scope *Scope) {
 		results = indirect(reflect.ValueOf(value))
 	}
 
-	if kind := results.Kind(); kind == reflect.Slice {
+	if results.Kind() == reflect.Interface {
-		isSlice = true
+		// for reflect params
-		resultType = results.Type().Elem()
+		slicev = results.Elem()
-		results.Set(reflect.MakeSlice(results.Type(), 0, 0))
+	} else {
+		// for struct params
+		slicev = results
+	}
 
+	if kind := slicev.Kind(); kind == reflect.Slice {
+		isSlice = true
+		resultType = slicev.Type().Elem()
+		slicev = slicev.Slice(0, slicev.Cap())
 		if resultType.Kind() == reflect.Ptr {
 			isPtr = true
 			resultType = resultType.Elem()
@@ -63,11 +75,11 @@ func queryCallback(scope *Scope) {
 		if str, ok := scope.Get("gorm:query_option"); ok {
 			scope.SQL += addExtraSpaceIfExist(fmt.Sprint(str))
 		}
-
 		if rows, err := scope.SQLDB().Query(scope.SQL, scope.SQLVars...); scope.Err(err) == nil {
 			defer rows.Close()
 
 			columns, _ := rows.Columns()
+			i := 0
 			for rows.Next() {
 				scope.db.RowsAffected++
 
@@ -75,18 +87,20 @@ func queryCallback(scope *Scope) {
 				if isSlice {
 					elem = reflect.New(resultType).Elem()
 				}
-
 				scope.scan(rows, columns, scope.New(elem.Addr().Interface()).Fields())
-
 				if isSlice {
 					if isPtr {
-						results.Set(reflect.Append(results, elem.Addr()))
+						slicev = reflect.Append(slicev, elem.Addr())
 					} else {
-						results.Set(reflect.Append(results, elem))
+						slicev = reflect.Append(slicev, elem)
+					}
+					slicev = slicev.Slice(0, slicev.Cap())
+					i++
 				}
 			}
+			if isSlice {
+				results.Set(slicev.Slice(0, i))
 			}
-
 			if err := rows.Err(); err != nil {
 				scope.Err(err)
 			} else if scope.db.RowsAffected == 0 && !isSlice {

model_struct.go

@@ -149,12 +149,24 @@ func getForeignField(column string, fields []*StructField) *StructField {
 // GetModelStruct get value's model struct, relationships based on struct and tag definition
 func (scope *Scope) GetModelStruct() *ModelStruct {
 	var modelStruct ModelStruct
+	var reflectType reflect.Type
 	// Scope value can't be nil
 	if scope.Value == nil {
 		return &modelStruct
 	}
 
-	reflectType := reflect.ValueOf(scope.Value).Type()
+	if reflect.ValueOf(scope.Value).Kind() != reflect.Ptr {
+		panic("results argument must be a ptr or slice")
+	}
+
+	if reflect.ValueOf(scope.Value).Elem().Kind() == reflect.Interface {
+		// for reflect params
+		reflectType = reflect.ValueOf(scope.Value).Elem().Elem().Type()
+	} else {
+		// for struct params
+		reflectType = reflect.ValueOf(scope.Value).Type()
+	}
+
 	for reflectType.Kind() == reflect.Slice || reflectType.Kind() == reflect.Ptr {
 		reflectType = reflectType.Elem()
 	}