Re: Error in Documentation? (Subqueries in CHECK Constraints / SQL92-Assertions)
Fred Toussi <[email protected]>
| Newsgroups | gmane.comp.java.hsqldb.user |
|---|---|
| Message-ID | <1361655225.19775.140661195868309.6DC627D3@webmail.messagingengine.com> |
Whatever we support will be correct according to the Standard. This type of constraint would be enforced at statement level or at commit. Fred On Sat, Feb 23, 2013, at 21:13, Timmy Turner wrote: Yes it's a complicated matter. If you are still accepting feature requests for this, the 2 things that Microsoft's solutions currently don't offer are: 1. Deferring the constraint evaluation to the end of the transaction 2. Evaluating the constraint on a statement/table-level and not for each individual row It would be great if you could include those. 2013/2/23 Fred Toussi <[1][email protected]> It will support a wide range of subquries but not necessarily all possible subqueries, as a check condition must hold when referenced tables are modified. Fred On Sat, Feb 23, 2013, at 20:56, Timmy Turner wrote: > We will probably add some support in this area later this year. Wow, this was unexpected. Can you provide any further details on what this might look like, or what amount of functionality you will be trying to cover? That would add HSQLDB to the list of currently only 2 SQL-based DBMSes that somewhat support this (one being MS Access/JET(1) and the other MS SQLServer(2)). (1) [2]http://support.microsoft.com/kb/201888/en-us (2) [3]http://sqlblog.com/blogs/alexander_kuznetsov/archive/2009/06/25/scal ar-udfs-wrapped-in-check-constraints-are-very-slow-and-may-fail-for-mul tirow-updates.aspx (Found those links on [4]http://stackoverflow.com/questions/6368349/why-dont-dbmss-support -assertion ) 2013/2/23 Fred Toussi <[5][email protected]> The documentation states the Standard and mentions any difference in implementation. In this case it misses the fact that subqueries are not yet supported in check constraints. We will probably add some support in this area later this year. Fred On Sat, Feb 23, 2013, at 20:31, Timmy Turner wrote: Hi, on [6]http://hsqldb.org/doc/2.0/guide/databaseobjects-chapt.html#dbc_co nstraints (or page 48 in the PDF) it says: "A CHECK constraint consists of a <search condition> that must not be false (can be unknown) for each row of the table. The <search condition> can reference all the columns of the current row, and if it contains a <subquery>, other tables and views in the database (excluding its own table)." Is this actually true or an error in the documentation? Trying a subquery in a check constraint gives me a FeatureNotSupportedException. Are there any plans to support this functionality (or Assertions in general) in the near future? ----------------------------------------------------------------------- ------- Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: [7]http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Hsqldb-user mailing list [8][email protected] [9]https://lists.sourceforge.net/lists/listinfo/hsqldb-user -------------------------------------------------------------------- ---------- Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: [10]http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Hsqldb-user mailing list [11][email protected] [12]https://lists.sourceforge.net/lists/listinfo/hsqldb-user ----------------------------------------------------------------------- ------- Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: [13]http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Hsqldb-user mailing list [14][email protected] [15]https://lists.sourceforge.net/lists/listinfo/hsqldb-user -------------------------------------------------------------------- ---------- Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: [16]http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Hsqldb-user mailing list [17][email protected] [18]https://lists.sourceforge.net/lists/listinfo/hsqldb-user ----------------------------------------------------------------------- ------- Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: [19]http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Hsqldb-user mailing list [20][email protected] [21]https://lists.sourceforge.net/lists/listinfo/hsqldb-user References 1. mailto:[email protected] 2. http://support.microsoft.com/kb/201888/en-us 3. http://sqlblog.com/blogs/alexander_kuznetsov/archive/2009/06/25/scalar-udfs-wrapped-in-check-constraints-are-very-slow-and-may-fail-for-multirow-updates.aspx 4. http://stackoverflow.com/questions/6368349/why-dont-dbmss-support-assertion 5. mailto:[email protected] 6. http://hsqldb.org/doc/2.0/guide/databaseobjects-chapt.html#dbc_constraints 7. http://p.sf.net/sfu/appdyn_d2d_feb 8. mailto:[email protected] 9. https://lists.sourceforge.net/lists/listinfo/hsqldb-user 10. http://p.sf.net/sfu/appdyn_d2d_feb 11. mailto:[email protected] 12. https://lists.sourceforge.net/lists/listinfo/hsqldb-user 13. http://p.sf.net/sfu/appdyn_d2d_feb 14. mailto:[email protected] 15. https://lists.sourceforge.net/lists/listinfo/hsqldb-user 16. http://p.sf.net/sfu/appdyn_d2d_feb 17. mailto:[email protected] 18. https://lists.sourceforge.net/lists/listinfo/hsqldb-user 19. http://p.sf.net/sfu/appdyn_d2d_feb 20. mailto:[email protected] 21. https://lists.sourceforge.net/lists/listinfo/hsqldb-user ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_feb _______________________________________________ Hsqldb-user mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/hsqldb-user