[Phpmyadmin-devel] Display multiple query results

[Rouslan Placella]

On 07/18/2012 02:16 PM, Michal Čihař wrote:
> Hi
>
> Dne Tue, 17 Jul 2012 10:38:32 +0530
> Chanaka Dharmarathna <pe.chanaka.ck at gmail.com> napsal(a):
>
>> I'm trying to implement titled case related to bug [0].
>> In current code, any SQL going to executed via SQL window, is processed and
>> if there are more SQL queries, it detect only one query.
>> So whole statement with any valid number of SQl queries need to be detected.
>> Then by using mysql_multi_query() function all results related to multiple
>> queries can be obtained.
>> As I think displaying these results can be done with looping the result
>> sets.
>>
>> Additionally I saw mysql_multi_query manual [1] mentioned that separate
>> queries are identified by semicolon.
>> May be I need to replace the delimiter if it is not a semicolon.
>
> It is not possible to replace it in all cases - eg. when creating
> procedures. So it might be better to run mysqli_query and collect
> results manually?
>
> I think Rouslan might have some ideas here as well as he is quite
> familiar with stored procedures and related stuff.

I'm not too sure what the question is, but I can explain the current 
state of the support for stored routines, which might be of help. First 
of all, the mysql extension does not support multiple result sets, so 
it's possible to execute stored routines that return one result set 
only. Drizzle has no support for stored routines, so you don't need to 
worry about that either.
Now onto the more interesting stuff. The support for executing stored 
routines in pma is quite incomplete. The relevant code can  be found in 
the file libraries/rte/rte_rtoutines.lib.php, around line 1260 [0]. At 
the time that I was writing that code, I was convinced that a stored 
routines could only ever return one row of data (there is even a comment 
in the code stating this). Later I discovered that not only this was not 
true, and there could be multiple rows returned, but that it is even 
possible to return multiple sets of rows. So, I 've actually only 
implemented enough of the multi query support so that the "COMMANDS OUT 
OF SYNC" error is not thrown by MySQL when executing the routines.

As a practical example, let say that you have the following routine in 
the sakila db:

CREATE PROCEDURE `test`()
BEGIN
SELECT 1;
SELECT 2;
SELECT 3;
END

The code required to display all of it's results would be:

<?php
// standalone file, somewhere in the pma root folder
include 'libraries/common.inc.php';
PMA_DBI_select_db("sakila");
$query = "CALL test();";
$resource = mysqli_multi_query($GLOBALS['userlink'], $query);
$i = 0;
do {
     if ($result = mysqli_use_result($GLOBALS['userlink'])) {
         echo "result " . ++$i . "<br />";
         while ($row = mysqli_fetch_row($result) ) {
             printf("%s<br />", $row[0]);
         }
     }
} while(PMA_DBI_more_results() && PMA_DBI_next_result());
?>

As can be seen in the above code, some of the function calls are missing 
in our database abstraction layer and instead native mysqli function 
calls are used. These missing functions need to be implemented first. 
Btw, the above code is not a straight fit for how to execute the 
routines in pma, as there are other queries that need to be run, etc, 
etc. However it should give a good idea of what's missing.

Bye,
Rouslan

[0]: 
https://github.com/phpmyadmin/phpmyadmin/blob/master/libraries/rte/rte_routines.lib.php#L1260