Maximum length of MySQL query?

[Bert Sierra]

Does anyone know if there's an upper limit to the length of the query
string supplied to the mysql_query() function? It appears that strings
themselves can go well beyond 65,536 characters: the PHP manual does not
seem to specify the upper limit, but in one test I was able to construct
a 1,000,960 character string without a hitch.

The queries my code will construct will be considerable smaller --
between 3,500 characters and roughly 20,000 characters. Can anyone tell
me if a 20,000-character UPDATE will cause problems, given the code
below and assuming that the $updateSQL string contains valid MySQL code:

$database_VoIP_ Connection = ...;
$VoIP_Connectio n = ...;
$updateSQL = "UPDATE ... SET ... WHERE ...";
mysql_select_db ($database_VoIP _Connection, $VoIP_Connectio n);
$Result1 = mysql_query($up dateSQL, $VoIP_Connectio n) or
die(mysql_error ());

I can chop up the query into smaller pieces if need be, but I'd rather
execute a single UPDATE for speed and simplicity.


-- Bert Sierra
Tempered MicroDesigns
Prescott, AZ

[py]

Re: Maximum length of MySQL query?

Bert Sierra wrote:[color=blue]
> Does anyone know if there's an upper limit to the length of the query
> string supplied to the mysql_query() function? It appears that strings
> themselves can go well beyond 65,536 characters: the PHP manual does not
> seem to specify the upper limit, but in one test I was able to construct
> a 1,000,960 character string without a hitch.
>
> The queries my code will construct will be considerable smaller --
> between 3,500 characters and roughly 20,000 characters. Can anyone tell
> me if a 20,000-character UPDATE will cause problems, given the code
> below and assuming that the $updateSQL string contains valid MySQL code:
>
> $database_VoIP_ Connection = ...;
> $VoIP_Connectio n = ...;
> $updateSQL = "UPDATE ... SET ... WHERE ...";
> mysql_select_db ($database_VoIP _Connection, $VoIP_Connectio n);
> $Result1 = mysql_query($up dateSQL, $VoIP_Connectio n) or
> die(mysql_error ());
>
> I can chop up the query into smaller pieces if need be, but I'd rather
> execute a single UPDATE for speed and simplicity.
>
>
> -- Bert Sierra
> Tempered MicroDesigns
> Prescott, AZ[/color]

20,000-character should work fine with mysql > 4

Look here for more info:

http://www.devshed.com/c/a/MySQL/Troubleshooting-Problems-with-MySQL-Programs/4/

py