Can I add triggers and indexes to the tables created by SQList?

In principle, the tables created by SQList should not be altered, both in their structure and the data they contain. Doing that could interfere with the correct functioning of SQList.

However, sometimes is becomes necessary to add some indexes and/or triggers to those table to support business processes of increase performances.

If you plan to add indexes and/or triggers, be aware of the following restrictions:

• do not add referential integrity keys (aka foreign keys): SQList does not follow a precise order in updating the various tables, therefore it can synchronise a table containing a foreign key before it synchronises it's primary key table;
• do not add unique keys: SQList doe snot follow a precise order when inserting/modifying items and removing deleted items from the SQL table, therefore if could temporarily create a duplicate value in the key;
• do no add "not null" constraints: constraints on columns should be added to the SharePoint list, no to the SQL table as SQList will exports "whatever it finds" in the list, therefore if could export null values for any columns (e.g. e newly added columns);
• wrap triggers in try/catch block, so that a failing trigger will not sop SQList updating the table (unless that is what you intend).

If any errors are caused by custom indexes and triggers, SQList will fail to update the table and try again on the next cycle, so no data will go out of synch. However, if you fail to notice these errors you will fined that the data in the SQL tables are not up-to-date.

Also note that problems causes by customisations to the the tables generated by SQList are not covered with our support included with the product.