Re: patch (for 9.1) string functions

Hello

I have a one idea nonstandard enhancing of sprintf - relatie often job
is a quoting in PostgreSQL. So sprintf should have a special formats
for quoted values. What do you think about

%lq ... literal quoted
%iq ... ident quoted

??

Regards

Pavel

2010/7/13 Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>:
> Hello
>
> 2010/7/13 Itagaki Takahiro <itagaki(dot)takahiro(at)gmail(dot)com>:
>> 2010/7/13 Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com>:
>>> so this is actualised patch:
>>> * concat_sql removed
>>> * left, right, reverse and concat are in core
>>> * printf and concat_ws are in contrib
>>> * format show "<NULL>" as NULL string
>>> * removed an using of wide chars
>>
>> I think function codes in the core (concat, format, left, right,
>> and reverse) are ready for committers. They also have docs, but
>> the names are not listed in Index page (bookindex.html).
>> Please add
>>   <indexterm>
>>    <primary>funcname</primary>
>>   </indexterm>
>> in func.sgml for each new function.
>>
>
> fixed
>> However, I have a couple of comments to stringfunc module. sprintf()
>> and concat_ws() are not installed by default, but provided by the module.
>>
>>> todo:
>>> NULL handling for printf function
>>
>> I like <NULL> for null arguments. It is just same as format() and RAISE.
>
> done
>
>>
>> === Questions ===
>> * concat_ws() transforms NULLs into empty strings.
>> Is it an intended behavior and compatible with MySQL?
>> Note that string_agg() doesn't add separators to NULLs.
>>
>
> no I was  wrong - original concat_ws just ignore NULL - fixed, now
> concat_ws has same behave like original.
>
>>  =# SELECT coalesce(concat_ws(',', 'A', NULL, 'B'), '(null)');
>>   coalesce
>>  ----------
>>   A,,B
>>  (1 row)
>>
>> * concat_ws() returns NULL when the separator is NULL.
>> Is it an intended behavior and compatible with MySQL?
>>
>>  =# SELECT coalesce(concat_ws(NULL, 'A', NULL, 'B'), '(null)');
>>   coalesce
>>  ----------
>>   (null)
>>  (1 row)
>>
>> === Trivial issues ===
>> * Some function prototypes are declared but not used.
>>  We can just remove them.
>>  - mb_string_info()
>>  - stringfunc_concat(PG_FUNCTION_ARGS);
>>  - stringfunc_left(PG_FUNCTION_ARGS);
>>  - stringfunc_right(PG_FUNCTION_ARGS);
>>  - stringfunc_reverse(PG_FUNCTION_ARGS);
>>
>> * Some error messages need to be improved.
>>  For example, "1th" is wrong.
>>    =# select sprintf('>>>%*s<<<', NULL, 'abcdef');
>>    ERROR:  null value not allowed
>>    HINT:  width (1th) arguments is NULL
>
> have you a some idea about it?
>
>>
>> * sprintf() has some typos in error messages
>>  For example, "sprinf".
>>
>
> fixed
>
>> --
>> Itagaki Takahiro
>>
>
> Regards
>
> Pavel
>