9 // Define callbacks for querying
11 DefaultCallback.Query().Register("gorm:query", queryCallback)
12 DefaultCallback.Query().Register("gorm:preload", preloadCallback)
13 DefaultCallback.Query().Register("gorm:after_query", afterQueryCallback)
16 // queryCallback used to query data from database
17 func queryCallback(scope *Scope) {
18 if _, skip := scope.InstanceGet("gorm:skip_query_callback"); skip {
22 //we are only preloading relations, dont touch base model
23 if _, skip := scope.InstanceGet("gorm:only_preload"); skip {
27 defer scope.trace(NowFunc())
31 resultType reflect.Type
32 results = scope.IndirectValue()
35 if orderBy, ok := scope.Get("gorm:order_by_primary_key"); ok {
36 if primaryField := scope.PrimaryField(); primaryField != nil {
37 scope.Search.Order(fmt.Sprintf("%v.%v %v", scope.QuotedTableName(), scope.Quote(primaryField.DBName), orderBy))
41 if value, ok := scope.Get("gorm:query_destination"); ok {
42 results = indirect(reflect.ValueOf(value))
45 if kind := results.Kind(); kind == reflect.Slice {
47 resultType = results.Type().Elem()
48 results.Set(reflect.MakeSlice(results.Type(), 0, 0))
50 if resultType.Kind() == reflect.Ptr {
52 resultType = resultType.Elem()
54 } else if kind != reflect.Struct {
55 scope.Err(errors.New("unsupported destination, should be slice or struct"))
59 scope.prepareQuerySQL()
61 if !scope.HasError() {
62 scope.db.RowsAffected = 0
63 if str, ok := scope.Get("gorm:query_option"); ok {
64 scope.SQL += addExtraSpaceIfExist(fmt.Sprint(str))
67 if rows, err := scope.SQLDB().Query(scope.SQL, scope.SQLVars...); scope.Err(err) == nil {
70 columns, _ := rows.Columns()
72 scope.db.RowsAffected++
76 elem = reflect.New(resultType).Elem()
79 scope.scan(rows, columns, scope.New(elem.Addr().Interface()).Fields())
83 results.Set(reflect.Append(results, elem.Addr()))
85 results.Set(reflect.Append(results, elem))
90 if err := rows.Err(); err != nil {
92 } else if scope.db.RowsAffected == 0 && !isSlice {
93 scope.Err(ErrRecordNotFound)
99 // afterQueryCallback will invoke `AfterFind` method after querying
100 func afterQueryCallback(scope *Scope) {
101 if !scope.HasError() {
102 scope.CallMethod("AfterFind")