Checking SQL assertions

A system for a Relational Database Management System, RDMS, to compile an SQL assertion into a set of SQL statements or views configured to check, at run-time, post-update satisfaction of the SQL assertion which means satisfaction of the SQL assertion after execution of an SQL update;

• the RDMS SQL assertions including the SQL assertion to be checked and relational tables having a consistent pre-update state, which means that the SQL assertions are satisfied before execution of the SQL update;
• the SQL update and the SQL assertion to be checked affect or refer to one or more of the relational tables having a pre-update content which means content before execution of the SQL update;
• the system comprising:
• a processor, and
• a memory storing executable instructions that, when executed by the processor, cause the system to perform a method of:
• creating, by execution of a CREATE TRIGGER statement, one or more SQL database triggers configured to simulate, at run-time, execution of the SQL update by providing one or more prospective relational tables, which are distinct from the affected relational tables, with a differential or modified content to be caused by execution of the SQL update, while keeping unaltered the pre-update content of the affected relational tables;
• converting the SQL assertion to be checked into SQL statements or views configured to determine, at run-time, satisfaction or dissatisfaction of the SQL assertion depending on the pre-update content of the affected relational tables and the differential or modified content of the prospective relational tables;
• and
• creating a procedure configured to commit or abort, at an end of a transaction corresponding to the SQL update, execution of the SQL update onto the affected relational tables depending on whether the SQL assertion to be checked has been determined satisfied or dissatisfied, respectively.