Re: How to set parameters in 'options'?

On 1/29/19 10:03 AM, Stefan Keller wrote:
> Many thanks to Igor and Adrian for your hints.
> 
> Got it to work like this:
> 
> create function link_server(_server text, _host text, _port text, _dbname text)
> returns void as $$
> begin
>    execute format('create server %s
>      foreign data wrapper postgres_fdw
>      options (host %L, port %L, dbname %L)', _server, _host, _port, _dbname);
> end;
> $$ language plpgsql;

I would go with %I instead of %s for _server.

> 
> select link_server('other_db_server', '111.11.11.11', '5432', 'other_db');
> 
> But I actually hoped being able avoid "execute"...

Why?

> 
> :Stefan
> 
> Am Di., 29. Jan. 2019 um 16:21 Uhr schrieb Adrian Klaver
> <adrian.klaver@aklaver.com>:
>>
>> On 1/29/19 6:40 AM, Stefan Keller wrote:
>>> Hi,
>>>
>>> I'd like to write a function like this:
>>>
>>> create function foo(_host text, _port text, _dbname text)
>>> returns void as $$
>>>     create server _server
>>>       foreign data wrapper postgres_fdw
>>>       options (host _host, port _port, dbname _dbname);
>>>       -- ERROR: syntax error at or near "_host"
>>> $$ language sql;
>>>
>>> In order to e.g. do:
>>> select foo('111.11.11.11', '5432', 'mydb');
>>>
>>> How can I set the parameters in 'options' using those variables?
>>
>> If you are going to use plpgsql, then format:
>>
>> https://www.postgresql.org/docs/10/functions-string.html#FUNCTIONS-STRING-FORMAT
>>
>> https://www.postgresql.org/docs/10/plpgsql-statements.html#PLPGSQL-QUOTE-LITERAL-EXAMPLE
>>
>> So something like:
>>
>> execute format('create server _server
>>       foreign data wrapper postgres_fdw
>>       options (host $1, port $2, dbname $3') USING _host, _port, _dbname
>>
>> Not sure where the _server is coming from so that might have to be dealt
>> with.
>>
>>>
>>> :Stefan
>>>
>>> P.S. Actually I'll put this code in a plggsql function later on.
>>>
>>>
>>
>>
>> --
>> Adrian Klaver
>> adrian.klaver@aklaver.com
> 


-- 
Adrian Klaver
adrian.klaver@aklaver.com