[libgda] Using error for unsupported operation

[Pavlo Solntsev <psolntsev src gnome org>]

commit c5d2aa59794a1507e291bf59e6c4cf4e6fe023b1
Author: Pavlo Solntsev <p sun fun gmail com>
Date:   Thu May 28 13:04:40 2020 -0500

    Using error for unsupported operation

 libgda/gda-db-column.c | 4 ++++
 1 file changed, 4 insertions(+)
---
diff --git a/libgda/gda-db-column.c b/libgda/gda-db-column.c
index 6b50a0e68..e6d1d49cf 100644
--- a/libgda/gda-db-column.c
+++ b/libgda/gda-db-column.c
@@ -1404,6 +1404,10 @@ gda_db_column_drop (GdaDdlModifiable *self,
                     gpointer user_data,
                     GError **error)
 {
+  g_set_error (error, GDA_DDL_MODIFIABLE_ERROR,
+               GDA_DDL_MODIFIABLE_NOT_IMPLEMENTED,
+               _("Operation is not implemented for the used provider"));
+
   return FALSE;
 }