-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Patrick Duda wrote: > I guess I don't understand this locking stuff. I have a InnoDB table > that has one thing in it, a counter. All I want to do is have multiple > instances of the code read this counter and increment it. I want to > make sure that each one is unique. > > Here is what I am doing in java: > > c.setAutoCommit(false); > ... > rs = statement.executeQuery("select request_id from requestid_innodb for > update"); > ... > String updateQuery = "update requestid_innodb set request_id="; > updateQuery = updateQuery + nextRequestId; > tempStatement = c.createStatement(); > tempStatement.executeUpdate(updateQuery); > ... > c.commit(); > c.setAutoCommit(true); > > If I have multiple instances of this code running I end up with > duplicate keys. I thought this was suppose to lock the table so that > would not happen. > > What am I not doing right? What am I not understanding about locking? > > Thanks > > Patrick > >
Patrick, Are you sure the table is using the InnoDB storage engine? What does the output of "SHOW CREATE TABLE " for the table in question say? -Mark -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFD7OF/tvXNTca6JD8RAjS0AJwKoXIpZUVY3Z0g/vqcUbyxm6JzBwCeIC7Z f1Tgh6gQde3w7KtGRCU3H/0= =j0x0 -----END PGP SIGNATURE----- -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]