Index: lams_tool_scratchie/src/java/org/lamsfoundation/lams/tool/scratchie/dbupdates/patch20150903.sql
===================================================================
diff -u
--- lams_tool_scratchie/src/java/org/lamsfoundation/lams/tool/scratchie/dbupdates/patch20150903.sql	(revision 0)
+++ lams_tool_scratchie/src/java/org/lamsfoundation/lams/tool/scratchie/dbupdates/patch20150903.sql	(revision 068aa1bfaf201f8ae0c19e1bb0153f77efb7bc3f)
@@ -0,0 +1,14 @@
+-- Turn off autocommit, so nothing is committed if there is an error
+SET AUTOCOMMIT = 0;
+SET FOREIGN_KEY_CHECKS=0;
+----------------------Put all sql statements below here-------------------------
+
+-- LDEV-3548 Prevent Scratchie tool from storing duplicate scratches done by the same user
+ALTER TABLE `tl_lascrt11_answer_log` ADD UNIQUE `FK_NEW_lascrt11_30113BFC309ED321`(`scratchie_answer_uid`, `session_id`);
+
+----------------------Put all sql statements above here-------------------------
+
+-- If there were no errors, commit and restore autocommit to on
+COMMIT;
+SET AUTOCOMMIT = 1;
+SET FOREIGN_KEY_CHECKS=1;