Index: lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch20230219.sql
===================================================================
diff -u
--- lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch20230219.sql	(revision 0)
+++ lams_common/src/java/org/lamsfoundation/lams/dbupdates/patch20230219.sql	(revision cf9a4805b365e1b25a985f5d2142e13355c2ca81)
@@ -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
+
+-- SP-4 Prevent duplicates in ext user mapping table
+ALTER TABLE lams_ext_user_userid_map ADD UNIQUE KEY UQ_lams_ext_user_userid_map_1 (ext_server_org_map_id, external_username);
+
+-- 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;