refs #16234 [fid_adlr] changes in DB migration script

* drop column username_id after copying to username
* drop user_id_key unique key constraint
* set default values on columns firstname, lastname, cat_username

module/fid_adlr/sql/migrations/mysql/migrateData_Vufind1ToVufind5_First_Adlr.sql

@@ -93,9 +93,21 @@ ALTER TABLE user
   MODIFY COLUMN expiry_date datetime NOT NULL DEFAULT '2000-01-01 00:00:00', 
   MODIFY COLUMN created datetime NOT NULL DEFAULT '2000-01-01 00:00:00';
 
+-- Drop unique key contraint involving columns "username" and "username_id"
+
+ALTER TABLE user DROP INDEX user_id_key;
+
+-- Fill column "username" with content of column "username_id" and set default values for columnls firstname, lastname, cat_username
+
+UPDATE user SET username=username_id,
+                firstname='',
+                lastname='',
+                cat_username=NULL;
+
 -- Drop columns which are not part of the vufind5 structure anymore
 
 ALTER TABLE user
+  DROP COLUMN username_id,
   DROP COLUMN liberoid,               
   DROP COLUMN attention,              
   DROP COLUMN business_phone,         
@@ -121,10 +133,6 @@ ALTER TABLE user
   DROP COLUMN bibid,                  
   DROP COLUMN updated;
 
--- Fill column "username" with content of column "id"
-
-UPDATE user SET username=id;
-
 -- Set the password columns to default values for all rows
 
 UPDATE user SET password='';