Search found 124 matches
- Tue Apr 28, 2009 11:32 am
- Forum: Report a Bug
- Topic: Dbrowser error displaying negative integer
- Replies: 1
- Views: 4164
Dbrowser error displaying negative integer
The statement "output -2;" works fine but typing just -2 in the input pane results in an error message. (I discovered this bug while testing the COMPARE_TO operator provided in OperatorsChar.d. COMPARE_TO('Date','Darwen') results in 2 but comparing those two strings the other way around fa...
- Mon Mar 23, 2009 2:27 pm
- Forum: Report a Bug
- Topic: MAX of empty set causes internal error (sometimes)
- Replies: 2
- Views: 5369
MAX of empty set causes internal error (sometimes)
The current value of relvar SP is RELATION {S# CHARACTER, P# CHARACTER, Qty INTEGER} { TUPLE {S# "S1", P# "P1", Qty 300}, TUPLE {S# "S1", P# "P2", Qty 200}, TUPLE {S# "S1", P# "P3", Qty 400}, TUPLE {S# "S1", P# "P4", Qty...
- Tue Oct 21, 2008 11:34 am
- Forum: Rel's "DBrowser": The Rel Graphical User Interface
- Topic: chosen font not activated at startup
- Replies: 1
- Views: 8633
chosen font not activated at startup
I change the point size to 24 for lecture-room demos, but next time I start up Dbrowser I have to do Tools/Options/Save to get the selected font to show in the lower pane (even though the menu does show the point size to have been remembered). I note that changing the font doesn't affect the enhance...
- Tue Oct 21, 2008 11:30 am
- Forum: Report a Bug
- Topic: ctrl-tab in Dbrowser causes crash
- Replies: 2
- Views: 5491
ctrl-tab in Dbrowser causes crash
Just press ctrl-tab in Dbrowser, when the cursor is in the lower pane. You get a java.lang.StackOverflowError. Past releases of V3 all exhibit bad behaviour of some sort when you press Ctrl-tab. In V2 the cursor went to the location box and from there to one of the buttons.
Hugh
Hugh
- Mon Oct 20, 2008 10:50 am
- Forum: Report a Bug
- Topic: internal error on invalid attribute reference in SUMMARIZE
- Replies: 2
- Views: 5980
internal error on invalid attribute reference in SUMMARIZE
Many thanks for 0.3.13, which I was using when I stumbled on this one. In the expression below the second <summarize add> invalidly references an attribute defined in the first. The situation gave rise to an internal error as shown instead of a regular error message. Hugh summarize relation{tuple{a ...
- Mon Oct 13, 2008 5:34 pm
- Forum: Report a Bug
- Topic: Strange info message after failed INSERT
- Replies: 3
- Views: 6890
Re: Strange info message after failed INSERT
Since I posted this one I've discovered that when an insert fails because of a mistake that gives rise to a constraint violation, and you then correct that mistake, the second insert reports twice as many tuples as it should have. It appears to have counted the ones on the failed insert as well as t...
- Mon Oct 06, 2008 2:58 pm
- Forum: Report a Bug
- Topic: relation comparison in WHERE clause gives wrong result
- Replies: 4
- Views: 7708
Re: relation comparison in WHERE clause gives wrong result
I should have added that the following equivalent expression, using GROUP, works fine, as you can see: (((EXAM_MARK{ALL BUT Mark} group ( {CourseId} AS G1)) RENAME (StudentId AS S1) join (EXAM_MARK{ALL BUT Mark} group ( {CourseId} AS G2)) RENAME (StudentId AS S2)) where G1 >= G2 and S1<>S2){ALL BUT ...
- Mon Oct 06, 2008 2:49 pm
- Forum: Report a Bug
- Topic: relation comparison in WHERE clause gives wrong result
- Replies: 4
- Views: 7708
relation comparison in WHERE clause gives wrong result
Using the same example as in my "join on RVA" post, also today: var EXAM_MARK base relation { StudentId CHAR, CourseId CHAR, Mark INTEGER } key {ALL BUT Mark}; EXAM_MARK := relation { tuple { StudentId 'S1', CourseId 'C1', Mark 85 }, tuple { StudentId 'S1', CourseId 'C2', Mark 49 }, tuple ...
- Mon Oct 06, 2008 12:22 pm
- Forum: Report a Bug
- Topic: join on RVA causes run-time exception
- Replies: 1
- Views: 5586
join on RVA causes run-time exception
The following script gave rise to the error in question. The first two statements just create and populate a relvar. The third one is a relational expression operating on that relvar. Rel appears to get the result type right but falls over in computing the result. var EXAM_MARK base relation { Stude...
- Fri Sep 26, 2008 3:05 pm
- Forum: Report a Bug
- Topic: Missing quote gives rise to slew of messages
- Replies: 1
- Views: 4740
Missing quote gives rise to slew of messages
The ERROR: line shown in my example below is correct, of course, but do we have to get all those Java messages too? It looked catastrophic, but in fact I was able to continue the Dbrowser session. (I inserted a line break in the ERROR: message because otherwise it got truncated in this copy.) Hugh '...
- Fri Sep 26, 2008 2:57 pm
- Forum: Report a Bug
- Topic: Strange info message after failed INSERT
- Replies: 3
- Views: 6890
Strange info message after failed INSERT
A certain INSERT statement was correctly rejected, as follows: insert SP relation{tuple{S# 'S99', P# 'P1',Qty 120}}; ERROR: Update will cause CONSTRAINT Ca to fail. Line 1, column 48 near '120' But when I next dropped the constraint in question, something funny happened, as you can see: drop CONSTRA...
- Tue Sep 23, 2008 5:01 pm
- Forum: Report a Bug
- Topic: Complex rel exp causes exception
- Replies: 1
- Views: 5335
Complex rel exp causes exception
The following expression (a solution to one of the exercises set to my 2nd-year undergrads at Warwick) gave rise to an error: WITH ( S RENAME ( S# AS SX ) ) AS RX , ( S RENAME ( S# AS SY ) ) AS RY : ( ( RX JOIN RY ) WHERE ( ( SP WHERE S# = SX ) { P# } ) = ( ( SP WHERE S# = SY ) { P# } ) ) { SX, SY }...
- Tue Sep 23, 2008 4:35 pm
- Forum: Discussion
- Topic: Tutorial D INIT clause still not supported on base relvars
- Replies: 1
- Views: 8046
Tutorial D INIT clause still not supported on base relvars
Perhaps there should be a special section for discussing Rel vs Tutorial D differences. IWBNI the one mentioned in my subject line were resolved one day! I mean something like: VAR S BASE RELATION { S# CHAR, Sname CHAR, Status INTEGER, City CHAR} KEY { S# } INIT ( RELATION { TUPLE { S# 'S1', Sname '...
- Wed Aug 20, 2008 3:19 pm
- Forum: Report a Bug
- Topic: Strange error messages
- Replies: 2
- Views: 6109
Re: Strange error messages
Here's another: tupple { c 'abc' } ERROR: Encountered " <STRING_LITERAL> "\'abc\' "" at line 1, column 12. Was expecting one of: "}" ... "," ... This kind of thing seems to happen whenever a key word is misspelled. The message treats some subsequent token as t...
- Wed Aug 20, 2008 3:09 pm
- Forum: Rel Examples
- Topic: Testing strings for numeric
- Replies: 4
- Views: 12531
Testing strings for numeric
When we get UDT support, teachers using Chris Date's "suppliers and parts" database would like to define types such as SNO (for supplier numbers of the form "Sn", where n is a sequence of digits). With this in mind I essayed the following Tutorial D operator definition: operator ...