Search found 124 matches

by HughDarwen
Mon Oct 14, 2013 5:34 pm
Forum: Report a Bug
Topic: WIBNIs re error messages and backup
Replies: 15
Views: 478048

Re: WIBNIs re error messages and backup

Thank you, Dave. In connection with (b), I can confirm that the problem was not caused by a deletion of unique.id. I used the wrongly sequenced backup to restore my database, copying-and-pasting from the backup file piece by piece. Then I immediately ran backup again and inspected the file. Again it...
by HughDarwen
Mon Oct 07, 2013 11:02 am
Forum: Report a Bug
Topic: WIBNIs re error messages and backup
Replies: 15
Views: 478048

WIBNIs re error messages and backup

I ran into a couple of problems recently, neither of which represents a bug exactly but I couldn't find a more suitable forum. 1. The statement "delete xyz;", where xyz is the name of a base relvar, gave rise to an error message telling me that an empty relation had been given for TUPLE FR...
by HughDarwen
Mon Oct 07, 2013 10:44 am
Forum: Language Issues
Topic: Relation valued parameters
Replies: 5
Views: 10620

Re: Relation valued parameters

See TTM Very Strong Suggestion 6.

Business System 12, an interpreter, supported such operators back in 1980.

Hugh
by HughDarwen
Tue Mar 26, 2013 11:50 am
Forum: Report a Bug
Topic: Defining simple view causes loop
Replies: 3
Views: 8819

Re: Defining simple view causes loop

Yes. I deleted those operator definitions and everything then worked fine.

Hugh
by HughDarwen
Sun Mar 24, 2013 4:27 pm
Forum: Report a Bug
Topic: Defining simple view causes loop
Replies: 3
Views: 8819

Defining simple view causes loop

When I create a new v1.0.10 database from the attached backup, various things I attempt to do bring about a loop, reflected by endless repetitions of mysterious messages in the DBrowser Monitor window, as shown in the attachment, loop.d. The third attachment, DefBaseRelvars.d, is one of the scripts ...
by HughDarwen
Wed Mar 13, 2013 4:30 pm
Forum: Discussion
Topic: Question re JAVA_HOME and JDK_HOME
Replies: 2
Views: 12984

Re: Question re JAVA_HOME and JDK_HOME

Many thanks for the clear advice, which worked fine and OperatorsChar.d was executed in a flash. I installed JDK V7.0.7 in a new directory and noticed that its bin subdirectory contains both java.exe and javac.eex. I placed this bin subdirectory in my PATH variable, replacing the previous entry for ...
by HughDarwen
Thu Mar 07, 2013 12:25 pm
Forum: Discussion
Topic: Question re JAVA_HOME and JDK_HOME
Replies: 2
Views: 12984

Question re JAVA_HOME and JDK_HOME

When I execute OperatorsChar.d, for example, the DBrowser monitor gives me repetitions of this message: NOTE: A 'tools.jar' or internal Java compiler can't be found. Make sure JAVA_HOME or JDK_HOME point to a JDK installation. Trying to find an external javac compiler as an alternative. It's only a ...
by HughDarwen
Sun Feb 17, 2013 4:33 pm
Forum: Report a Bug
Topic: multiple assignment problem
Replies: 4
Views: 10292

multiple assignment problem

Against the database that I'll send a backup of privately (because can't get "upload attachment" to work), the following two multiple assignments are equivalent but only the first one works. In version 2, the first line inserts the empty set even though the given expression evaluates to th...
by HughDarwen
Sat Dec 29, 2012 12:39 pm
Forum: Report a Bug
Topic: Expression in op def gives spurious syntax error
Replies: 3
Views: 9018

Re: Expression in op def gives spurious syntax error

If you are suggesting that our Tutorial D V1 syntax was unsound, then I'm glad we fixed it in V2 by introducing a colon to separate the <attribute assign> s from the WHERE clause. I suppose a name followed by an opening paren can be taken for the start of an operator invocation, which might explain ...
by HughDarwen
Fri Dec 28, 2012 5:28 pm
Forum: Report a Bug
Topic: Expression in op def gives spurious syntax error
Replies: 3
Views: 9018

Expression in op def gives spurious syntax error

A certain UPDATE command works fine in DBrowser. When I parameterise it in an operator definition, such that literals are replaced by parameter names, I get an error message that seems to be spurious. I found that enclosing the WHERE condition in parens fixed the problem. Below is an example, copied...
by HughDarwen
Mon May 14, 2012 2:46 pm
Forum: Report a Bug
Topic: Database unusable after exit from DBrowser
Replies: 2
Views: 7663

Database unusable after exit from DBrowser

I'll send a zip file for this separately. The problem, which has been occurring repeatedly with this particular database, is that when I've had an apparently successful DBrowser session in which I've done a few updates, the next time I try to run DBrowser I get the following message: Unable to estab...
by HughDarwen
Sun Apr 15, 2012 2:25 pm
Forum: Report a Bug
Topic: crash that goes away after backup/restore
Replies: 1
Views: 7001

crash that goes away after backup/restore

I'm having to send my (zipped) database folder by private email because the attachment is too large for here. Anyway, the problem concerns the invocation "Problemist not matching (SolvedBy union ComposedBy)" against this database, which has been subject to invocations of INSERT, UPDATE and...
by HughDarwen
Fri Dec 02, 2011 10:32 am
Forum: Rel Examples
Topic: Is SUBSTRING(CHAR, INT, INT) correctly defined?
Replies: 1
Views: 8230

Is SUBSTRING(CHAR, INT, INT) correctly defined?

I refer to the operator provided in OperatorsChar.d. SUBSTRING('abcde',3,4) returns 'd' when I was expecting 'de'. It seems that the start position is using origin 0 while the end position uses origin 1. Alternatively, the third operand is to be interpreted as "up to but not including"--re...
by HughDarwen
Fri Dec 02, 2011 10:15 am
Forum: Report a Bug
Topic: spurious error on selector invocation for a UDT value
Replies: 2
Views: 8698

Re: spurious error on selector invocation for a UDT value

Since I reported this "bug" a few minutes ago I discovered that SUBSTRING(CHAR, INTEGER, INTEGER) takes an end position rather than a length as the third operand. So this is in fact a user error and not a bug. However, can I change this into a suggestion for a more explanatory error messag...
by HughDarwen
Fri Dec 02, 2011 9:41 am
Forum: Report a Bug
Topic: spurious error on selector invocation for a UDT value
Replies: 2
Views: 8698

spurious error on selector invocation for a UDT value

The following type definition was accepted by Rel 1.07 beta: type time possrep { c char constraint LENGTH(c) = 5 AND IS_DIGITS(SUBSTRING(c,0,2)) AND IS_DIGITS(SUBSTRING(c,3,2)) AND SUBSTRING(c,2,1) = ':'}; However, time('17:52') results in ERROR: Failure executing external function: java.lang.reflec...