Some Help With A Query

[murfitUK]

I've inherited a mysql database and will eventually get around to sorting it out to a better format. I've got to do a couple of queries quickly but am struggling! Any help appreciated.The first table is called `addresses` and has two fields `id` and `description`. Simple enough: 1=Room 1, 2=Room2 etc.The second table is called `details` and has a field called `id` (just a normal auto-increment index), `room` into which is inserted the `addresses`.`id` number from the first table. There are two fields called `from` and `to` which hold dates in the format "2008-11-24" and a field called `status` which holds a value of "let" or "void". (There are other fields for the name of a tenant and the daily rent charge.)If, say, Mr Smith was there from 1st August 2008 to 20th Jan 2009, the fields would be:`id`=34 (or whatever)`room`=7 (taken from the other table)status`="let"`from`="2008-08-01"`to`=`2009-01-20"etcThere should be another line created when the property becomes void:`id`=35 (or whatever)`room`=7 (taken from other table)`status`="void"`from`="2009-01-21"`to`=NULL (I assume because the propery is still void)etc The NULL will then be updated if the property is let again.If a tenant is currently in residence:`id`=36 (or whatever)`room`=9 (taken from other table)`status`="let"`from`="2008-12-18"`to`=NULLOne of the reports I need to do now is to generate a list of properties that are void. I can easily select where `status`="void" and `to`=NULL but sometimes the table is not updated properly and they forget to create a "void" record after updating the "let" record with an end date. How do I do this? I only need the select the `room` field from the `details` table - I'll do the join to get the address later.(If I was starting from scratch I wouldn't set it up this way but for now need to work with what I've got.)

[Stefano]

.....One of the reports I need to do now is to generate a list of properties that are void. I can easily select where `status`="void" and `to`=NULL but sometimes the table is not updated properly and they forget to create a "void" record after updating the "let" record with an end date. How do I do this? I only need the select the `room` field from the `details` table - I'll do the join to get the address later.(If I was starting from scratch I wouldn't set it up this way but for now need to work with what I've got.)

i haven't anylized properly the issue (actualy too long and life too short) but when you write "..table is not updated properly" may be something is wrong at that point. Why shoudn't a table be updated properly, I can't help but think the program that manage that table doesn't work fine, or may be you need to add some trigger in mysql side.regardsstefano de boni