Update custom-database-queries.md

docs/user-documentation/general-admin-users/custom-database-queries.md

@@ -4,6 +4,10 @@ Custom Database Queries
 Introduction
 ------------
 
+```{warning}
+blablabla
+```
+
 openBIS application server can be configured to query any relational
 database server via SQL. There are three ways to use this feature in
 openBIS Web application: