Hi Nathan, If you have a compound primary key of say 7 columns and 6 of them are (or can be) blank or null then only the seventh column can be used as a "real" primary key.
So from an OJB point of view you could just solve the issue by declaring on the seventh column as primary key in the repository. I don't that it is a good idea to implement the feature you request because it fosters violations of the relational calculus. just my 2c, Thomas > -----Original Message----- > From: Nathan Smith [mailto:[EMAIL PROTECTED] > Sent: Friday, August 20, 2004 2:08 AM > To: [EMAIL PROTECTED] > Subject: Official implementation request. > > > Hi all, > > LabPro 2000 Ltd is a specialist provider of information management > systems including LIMS (Laboratory Information Management Systems). We > here at www.labpro2000.com currently use OJB as part of our eQual > application development (http://demo.labpro2000.com). This is a > redevelopment of the current application Labpro. To put it simply > LabPro, is a QA solution for any testing. > > We use an RDBMS developed by a little known company called Progress > (http://www.progress.com/progress/index.ssp). The RDBMS is a very good > database but not many people have heard of it, so it is not really > mainstream. > > The problem is this RDBMS allows records to be inserted with blank or > null values for fields of the primary key. For example we have a table > that uses 7 fields/columns as part of the PK. A record could > be inserted > with 6 of those fields blank or null. The use of the table is > a special > case as it defines range limits that testing results must fall within > for a particular product to be assigined a quality code. One of the > records in this table depending on what fields are blank can used for > multiple products. We also have another table which is used in similar > fashion > > The proposal: > Can the repository.xml contain some property or database specific > metadata element which can be used to determine whether > NULL's or blanks > can be used as ligitimate values for PK fields. Or maybe another way > would be to enable some sort of callback that can be > implemented through > the Platform interface. > > Look forward to hearing your ideas. > > > Nathan Smith > > Software Developer > LabPro 2000 Limited > Phone: +64 4 586 6840 > Facsimile: +64 4 586 6841 > <mailto:[EMAIL PROTECTED]> [EMAIL PROTECTED] > <http://www.labpro2000.com/> www.labpro2000.com > > Level 6, Riverside Tower on Daly, 15 Daly Street > Lower Hutt, New Zealand > > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
