diff --git a/lib/Database.php b/lib/Database.php
index 6c038ab..b7b4488 100644
--- a/lib/Database.php
+++ b/lib/Database.php
@@ -256,7 +256,8 @@ class Database {
             throw new User\Exception("alreadyExists", ["action" => __FUNCTION__, "user" => $user]);
         }
         $hash = (strlen($password) > 0) ? password_hash($password, \PASSWORD_DEFAULT) : "";
-        $this->db->prepare("INSERT INTO arsse_users(id,password,num) values(?, ?, coalesce((select max(num) from arsse_users), 0) + 1)", "str", "str")->runArray([$user,$hash]);
+        // NOTE: This roundabout construction (with 'select' rather than 'values') is required by MySQL, because MySQL is riddled with pitfalls and exceptions
+        $this->db->prepare("INSERT INTO arsse_users(id,password,num) select ?, ?, ((select max(num) from arsse_users) + 1)", "str", "str")->runArray([$user,$hash]);
         return true;
     }
 
diff --git a/sql/MySQL/6.sql b/sql/MySQL/6.sql
index fff5767..e16375c 100644
--- a/sql/MySQL/6.sql
+++ b/sql/MySQL/6.sql
@@ -2,5 +2,20 @@
 -- Copyright 2017 J. King, Dustin Wilson et al.
 -- See LICENSE and AUTHORS files for details
 
+alter table arsse_users add column num bigint unsigned unique;
+alter table arsse_users add column admin boolean not null default 0;
+alter table arsse_users add column lang longtext;
+alter table arsse_users add column tz varchar(44) not null default 'Etc/UTC';
+alter table arsse_users add column soort_asc boolean not null default 0;
+create temporary table arsse_users_existing(
+    id text not null,
+    num serial primary key
+) character set utf8mb4 collate utf8mb4_unicode_ci;
+insert into arsse_users_existing(id) select id from arsse_users;
+update arsse_users as u, arsse_users_existing as n
+    set u.num = n.num
+where u.id = n.id;
+drop table arsse_users_existing;
+alter table arsse_users modify num bigint unsigned not null;
 
 update arsse_meta set value = '7' where "key" = 'schema_version';
diff --git a/sql/PostgreSQL/6.sql b/sql/PostgreSQL/6.sql
index 4d86e98..6099e8d 100644
--- a/sql/PostgreSQL/6.sql
+++ b/sql/PostgreSQL/6.sql
@@ -2,6 +2,21 @@
 -- Copyright 2017 J. King, Dustin Wilson et al.
 -- See LICENSE and AUTHORS files for details
 
-
+alter table arsse_users add column num bigint unique;
+alter table arsse_users add column admin smallint not null default 0;
+alter table arsse_users add column lang text;
+alter table arsse_users add column tz text not null default 'Etc/UTC';
+alter table arsse_users add column soort_asc smallint not null default 0;
+create temp table arsse_users_existing(
+    id text not null,
+    num bigserial
+);
+insert into arsse_users_existing(id) select id from arsse_users;
+update arsse_users as u
+    set num = e.num
+from arsse_users_existing as e
+where u.id = e.id;
+drop table arsse_users_existing;
+alter table arsse_users alter column num set not null;
 
 update arsse_meta set value = '7' where "key" = 'schema_version';