feat: Update project structure and configuration files

backend/database/fields/common.go

@@ -0,0 +1,45 @@
+package fields
+
+import (
+	"database/sql/driver"
+	"encoding/json"
+	"errors"
+)
+
+// implement sql.Scanner interface
+type Json[T any] struct {
+	Data T `json:",inline"`
+}
+
+func ToJson[T any](data T) Json[T] {
+	return Json[T]{Data: data}
+}
+
+func (x *Json[T]) Scan(value interface{}) (err error) {
+	switch v := value.(type) {
+	case string:
+		return json.Unmarshal([]byte(v), &x)
+	case []byte:
+		return json.Unmarshal(v, &x)
+	case *string:
+		return json.Unmarshal([]byte(*v), &x)
+	}
+	return errors.New("Unknown type for ")
+}
+
+func (x Json[T]) Value() (driver.Value, error) {
+	return json.Marshal(x.Data)
+}
+
+func (x Json[T]) MarshalJSON() ([]byte, error) {
+	return json.Marshal(x.Data)
+}
+
+func (x *Json[T]) UnmarshalJSON(data []byte) error {
+	var value T
+	if err := json.Unmarshal(data, &value); err != nil {
+		return err
+	}
+	x.Data = value
+	return nil
+}