Lock on table

[tcardoso]

Hello

If I do:

1) mysql_query('LOCK TABLE tablename');
2) mysql_query('SELECT * from tablename where condition=0');
3) if (cond) {
4)  mysql_query('UPDATE tablename SET condition=1 WHERE condition=0');
5) }
6) mysql_query('UNLOCK TABLE tablename');

What happens when another process arrives on 1 and tablename is already locked it wait until the table is unlocked?

Imagine something go very wrong and the code its interrupted in 3) for example, the table will stay locked. How will I solve that/How can I implicity release all locks?

Thanks

 

[KingSlick]

At worse, you would need to use a mysql command line (ie. telnet or SSH in) and "UNLOCK TABLES;"

This is about all you would need to do

 

[tcardoso]

Sorry but you didn't answer my question. What happen when another process arrives on LOCK TABLE tablename and the tablename is already locked? He waits? for how long?

the lock table command returns any value? (success or error value)

Thanks

 

[KingSlick]

Sorry. From the tests that I ran on this, they continue to successfully lock the table. And returns a success message.

SM

 

[tcardoso]

Yes. but a table is locked, another process arrives the instruction to lock the table, and it can't access it (its locked). So does it wait until the table gets unlocked and it lock the table?

Thanks