Added support for custom string types.

Author: dsmontoya

statement.go

@@ -157,6 +157,8 @@ func (c converter) ConvertValue(v interface{}) (driver.Value, error) {
 		return int64(u64), nil
 	case reflect.Float32, reflect.Float64:
 		return rv.Float(), nil
+	case reflect.String:
+		return rv.String(), nil
 	}
 	return nil, fmt.Errorf("unsupported type %T, a %s", v, rv.Kind())
 }

statement_test.go

@@ -0,0 +1,13 @@
+package mysql
+
+import "testing"
+
+type customString string
+
+func TestConvertValueCustomTypes(t *testing.T) {
+	var cstr customString = "string"
+	c := converter{}
+	if _, err := c.ConvertValue(cstr); err != nil {
+		t.Errorf("custom string type should be valid")
+	}
+}