[Info-vax] Can DCL be enhanced to report why a qualifier is ambiguous ?

[Jan-Erik Söderholm]

Den 2021-05-29 kl. 12:04, skrev Phillip Helbig (undress to reply):
> In article <s8t1sq$f2e$1 at dont-email.me>,
> =?UTF-8?Q?Jan-Erik_S=c3=b6derholm?= <jan-erik.soderholm at telia.com>
> writes:
> 
>>>>> One of the Linux shells does spell checking. I think its a terrible idea.
>>>>
>>>> Like this?
>>>>
>>>> $ sql shwo table
>>>> %SQL-I-SPELLCORR, identifier SHWO replaced with SHOW
>>>> User tables in database with filename SQL$DATABASE
>>>>        ARTLAB
>>>>        DB_SUBMIT
>>>>        DW101T
>>>>        ...
>>>>        ...
>>>
>>> Now *that's* a bad idea -- automatically substituting what the user said
>>> with what s/he might have meant, although I suppose it can't do much
>>> damage in a show command.
> 
> With SHOW, there is little danger.
> 
>>> I hope that that "drool database" doesn't get
>>> automatically turned into "drop database" and there went the whole
>>> enchilada.
>>
>> SQL> crea datatase file test;
>> %SQL-I-SPELLCORR, identifier DATATASE replaced with DATABASE
>> SQL>
>>
>> SQL> drool datatase file test;
>> drool datatase file test;
>> ^
>> %SQL-F-LOOK_FOR_STMT, Syntax error, looking for a valid SQL
>> statement, found DROOL instead
>> SQL>
>>
>>
>> SQL> drol datatase file test;
>> %SQL-I-SPELLCORR, identifier DROL replaced with DROP
>> %SQL-I-SPELLCORR, identifier DATATASE replaced with DATABASE
>> SQL>
>>
>> Have worked like this for 20+ years and I guess there have never
>> been any reason to change it.
> 
> Note also that, in Rdb, not only are INSERT, DELETE, UPDATE, and
> (trivially) SELECT reversible via ROLLBACK, but also things like CREATE
> TABLE and, yes, even DROP DATABASE.  So even here there is not a huge
> danger.  Apparently the match has to be pretty close before it is
> replaced, and there is little possibility that the intent was actually
> something else.
> 

Yes, many things are possible to ROLLBACK, but dropping a database is
not one of those. FWIM...


>> Note that this is only in the interactive SQL interface, not when
>> using SQL in application code.
> 
> Right.
>