Method Changed

statement.go:643–696

Changed check model changed or not when updating

(fields ...string)

// Changed check model changed or not when updating
func (stmt *Statement) Changed(fields ...string) bool {
	modelValue := stmt.ReflectValue
	switch modelValue.Kind() {
	case reflect.Slice, reflect.Array:
		modelValue = stmt.ReflectValue.Index(stmt.CurDestIndex)
	}

	selectColumns, restricted := stmt.SelectAndOmitColumns(false, true)
	changed := func(field *schema.Field) bool {
		fieldValue, _ := field.ValueOf(stmt.Context, modelValue)
		if v, ok := selectColumns[field.DBName]; (ok && v) || (!ok && !restricted) {
			if mv, mok := stmt.Dest.(map[string]interface{}); mok {
				if fv, ok := mv[field.Name]; ok {
					return !utils.AssertEqual(fv, fieldValue)
				} else if fv, ok := mv[field.DBName]; ok {
					return !utils.AssertEqual(fv, fieldValue)
				}
			} else {
				destValue := reflect.ValueOf(stmt.Dest)
				for destValue.Kind() == reflect.Ptr {
					destValue = destValue.Elem()
				}
				if descSchema, err := schema.Parse(stmt.Dest, stmt.DB.cacheStore, stmt.DB.NamingStrategy); err == nil {
					if destField := descSchema.LookUpField(field.DBName); destField != nil {
						changedValue, zero := destField.ValueOf(stmt.Context, destValue)
						if v {
							return !utils.AssertEqual(changedValue, fieldValue)
						}
						return !zero && !utils.AssertEqual(changedValue, fieldValue)
					}
				}
			}
		}
		return false
	}

	if len(fields) == 0 {
		for _, field := range stmt.Schema.FieldsByDBName {
			if changed(field) {
				return true
			}
		}
	} else {
		for _, name := range fields {
			if field := stmt.Schema.LookUpField(name); field != nil {
				if changed(field) {
					return true
				}
			}
		}
	}

	return false
}

var matchName = func() func(tableColumn string) (table, column string) {
	nameMatcher := regexp.MustCompile(`^(?:\W?(\w+?)\W?\.)?(?:(\*)|\W?(\w+?)\W?)$`)