mysql-proxy-discuss team mailing list archive

[Kay Röpke <Kay.Roepke@xxxxxxx>]

Hi!

On Jan 15, 2009, at 6:58 PM, Giuseppe Maxia wrote:

> What is the recommended way of dealing with result sets in
> read_query_result?
> Previously, I used things like
>
>  local res = assert(inj.resultset)
>  local num_cols = string.byte(res.raw, 1)
>
>  if num_cols > 0 and num_cols < 255 then -- there is a resultset
>  -- some work
>  end
>
> Running this code, I now get warnings and different results than  
> before.
>
> Is there any change in the way we deal with resultsets?


Indeed there is.
This is a consequence of proxy no longer buffering resultsets by  
default to avoid overhead and memory size problems with large results.

In read_query you can tell it for which injections to buffer the  
result packets like:

proxy.queries:append(1, string.char(proxy.COM_QUERY) .. "SELECT value  
FROM table WHERE a > 5", { resultset_is_needed = true })

or do this for the original query:

proxy.queries:append(1, packet, { resultset_is_needed = true })

then the rest is as usual.

hth,
-k
--
Kay Roepke
Software Engineer, MySQL Enterprise Tools

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