exclusive row level lock in MySql

[muthu muruges]

how to create exlusive row level lock in mySQL database (db version 4.0 and database type is InnoDB). Please explain me thru' sql syntax.

[sandesh bangera]

Well in oracle, you would enter something like

sql> Select <columns> from <table> where <condition> FOR UPDATE;

This puts a Exclusive lock on the selected rows that will be release by either a commit / rollback;

If you fail to provide a where condition then the entire table is locked.

[muthu muruges]

what about in MySQL?,

I would like the locking query should work for the following scenario,
1) Having one DB connection
2) lock some rows by one thread
3) using the same connection lock some other rows by the second thread
4) release the lock aquired by the first thread, during this lock relase the second lock should not get relased
5) release the lock aquired by the second thread

is there any row level readlock or writelock exist in MySQL?

[muthu muruges]

any updates please.

[Jeanne Boyarsky]

Muthu,
According to the documentation, you get table level locking by default.