mysql write conflicts with concurrent connections

[ajetrumpet]

Hi all,

 

Yet another question for the experts here.  As in the subject to this thread, I'm interested in finding out how PHP handles concurrent database connections when the script has a write operation in it.  like for instance, this code:

 

$sql = "UPDATE table1 field = 'new value' WHERE field = 'old value'";
mysql_query($sql) or die('Update Failed!');

 

if I have 10 people loading one of my pages at the same time and I'm updating the same database table (with different records for each user) with an update statement, am I risking errors or even corruption because of the write-conflict issue??

 

It seems to me that PHP would act somewhat like an operating system here and sequence the requests so that doesn't happen.  True?

 

thanks so much!

[Christian F.]

This isn't handled by PHP, but the underlying database engine. For MySQL you can check out these links.

http://stackoverflow.com/questions/2217106/concurrent-mysql-database-queries

http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html

 

I'm sure, when moved to the correct section, that the resident MySQL expert(s) can fill out on whatever info I'm missing.