Re: string function - "format" function proposal - Mailing list pgsql-hackers

From Itagaki Takahiro
Subject Re: string function - "format" function proposal
Date
Msg-id AANLkTi=a6BAd6wTn2A6VVKmGwz4jThW8kRk+naDJARKd@mail.gmail.com
Whole thread Raw
In response to Re: string function - "format" function proposal  (Pavel Stehule <pavel.stehule@gmail.com>)
Responses Re: string function - "format" function proposal
List pgsql-hackers
On Wed, Sep 1, 2010 at 6:07 AM, Pavel Stehule <pavel.stehule@gmail.com> wrote:
> I don't found a nice mix for placeholders and positional placeholders

How about %pos$format, used in C-printf()? It might be
only in Linux's libc.

printf("<%2$s> <%1$d>\n", 123, "abc");
=> <abc> <123>
http://linux.die.net/man/3/printf

> %i ... sql identifier
> %v ... sql value
> %s ... string --- the most used tag I expect
> %l ... literal

Looks good designed.  I have a couple of comments and questions:

* There is no examples for %l. What's the difference from %v and %s? If it always quotes, how does it work? Like as
quote_literal()or quote_nullable()?
 

* %v quotes text values (and maybe all non-numeric values) with single quotes, but doesn't numeric values. How do we
determinethe difference? By type oid?
 

* %v also doesn't quote boolean values, but t and f are not valid. You should use true and false (or 't' and 'f') for
thecases. (So, your "INSERT INTO" example is broken.)
 

-- 
Itagaki Takahiro


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