Disciplines cannot be deleted due to Specify 7's uniquenessrule table

[grantfitzsimmons]

Attempting to delete a discipline in Specify 6 fails due to the following error:

com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Cannot delete or update a parent row: a foreign key constraint fails (`oakspring`.`uniquenessrule`, CONSTRAINT `uniquenessrule_DisciplineID_09ca1c68_fk_disciplin` FOREIGN KEY (`DisciplineID`) REFERENCES `discipline` (`UserGroupScopeId`))
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at com.mysql.jdbc.Util.handleNewInstance(Util.java:389)
	at com.mysql.jdbc.Util.getInstance(Util.java:372)
	at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:973)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3835)
	at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3771)
	at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2435)
	at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2582)
	at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2531)
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1618)
	at com.mysql.jdbc.StatementImpl.executeUpdate(StatementImpl.java:1549)
	at edu.ku.brc.specify.dbsupport.SpecifyDeleteHelper.deleteDiscipline(SpecifyDeleteHelper.java:1206)
	at edu.ku.brc.specify.dbsupport.SpecifyDeleteHelper.deleteRecords(SpecifyDeleteHelper.java:1101)
	at edu.ku.brc.specify.dbsupport.SpecifyDeleteHelper.delRecordFromTable(SpecifyDeleteHelper.java:510)
	at edu.ku.brc.specify.dbsupport.SpecifyDeleteHelper.delRecordFromTable(SpecifyDeleteHelper.java:452)
	at edu.ku.brc.specify.datamodel.busrules.DisciplineBusRules$6.doInBackground(DisciplineBusRules.java:548)
	at edu.ku.brc.specify.datamodel.busrules.DisciplineBusRules$6.doInBackground(DisciplineBusRules.java:539)
	at javax.swing.SwingWorker$1.call(SwingWorker.java:295)
	at java.util.concurrent.FutureTask.run(FutureTask.java:266)
	at javax.swing.SwingWorker.run(SwingWorker.java:334)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
	at java.lang.Thread.run(Thread.java:748)

Presumably the migration creates new records that Specify 6 is not aware of. This means that there is not currently a way to remove a discipline from within Specify itself if Specify 7 is used alongside Specify 6.

[realVinayak]

hmm setting the constraint to cascade instead of protect will fix this.. (on uniquenessrule table). I guess that we should have done it that way, anyways. We can still do this, via a migration..

I drop the constraint on uniquenessrule, and add a new one with cascade for it, when I need to delete disciplines.