diff --git a/modules/sqlauth/docs/sql.txt b/modules/sqlauth/docs/sql.txt
index ac7dbe314df3faffc5508dfdf6d750903b0c1b4e..3fb33818daf53690710970c8059e96eeaa9a2424 100644
--- a/modules/sqlauth/docs/sql.txt
+++ b/modules/sqlauth/docs/sql.txt
@@ -41,8 +41,8 @@ Database layout used in some of the examples:
       eduPersonPrincipalName TEXT NOT NULL
     );
     CREATE TABLE usergroups (
-      uid TEXT REFERENCES users (uid) ON DELETE CASCADE ON UPDATE CASCADE,
-      groupname TEXT,
+      uid VARCHAR(30) NOT NULL REFERENCES users (uid) ON DELETE CASCADE ON UPDATE CASCADE,
+      groupname VARCHAR(30) NOT NULL,
       UNIQUE(uid, groupname)
     );