Re: Truncate if exists

Hello

2012/10/12 Sébastien Lardière <slardiere(at)hi-media(dot)com>:
> On 10/11/2012 09:22 PM, Simon Riggs wrote:
>
>>>
>>> That is a lot more typing and it's not exactly intuitive. One obvious
>>> thing that would help is a function pg_table_exists(text) that would
>>> return true or false. But even with that there's a lot of syntactic
>>> sugar in there that is less than ideal: begin/end, dollar-quoting, do.
>>> Whatever becomes of this particular patch, I think we'd make a lot of
>>> people really happy if we could find a way to dispense with some of
>>> that stuff in simple cases.
>>
>> Yeh, definitely.
>>
>> So we just need a function called pg_if_table_exists(table, SQL) which
>> wraps a test in a subtransaction.
>>
>> And you write
>>
>> SELECT pg_if_table_exists('foo', 'TRUNCATE TABLE foo');
>>
>> and we can even get rid of all that other DDL crud that's been added....
>>
>> and we can have pg_if_table_not_exists() also.
>>
>
> If we can do something like :
>
> SELECT pg_if_table_exists('bar' , pg_if_table_exists('foo', 'TRUNCATE
> TABLE foo, bar, foobar')) ;
>
> or
>
> SELECT pg_if_tables_exists('TRUNCATE TABLE foo, bar, foobar', 'foo',
> 'bar') ;
>
> I say yes !

I don't like it in core - it can be used for SQL injection - it is dynamic SQL.

Regards

Pavel

>
>
> --
> Sébastien Lardière
> PostgreSQL DBA Team Manager
> Hi-Media
>
>
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