On 2015-04-08 06:00 PM, Dan Kennedy wrote: > On 04/08/2015 10:52 PM, R.Smith wrote: >> >> >> On 2015-04-08 05:38 PM, Dan Kennedy wrote: >>> On 04/08/2015 09:51 PM, R.Smith wrote: >>>> >>>> >>>> On 2015-04-08 04:18 PM, Fabian Pr?bstl wrote: >>>>> Hi there! >>>>> >>>>> Currently, we are using SQLite as our application file format for >>>>> a Windows 7/C#/System.Data.SQLite based desktop application. We >>>>> only allow one instance to open the file by running "set >>>>> locking_mode=EXCLUSIVE;BEGIN EXCLUSIVE;COMMIT" when connecting to >>>>> the database. >>>> >>>> BEGIN EXCLUSIVE - Locks the database from other SQLite3 database >>>> connections for the time being. >>>> COMMIT; - Unlocks it again - so calling all this in one go is >>>> pointless. >>> >>> Almost always correct. But the "PRAGMA locking_mode=EXCLUSIVE" thing >>> changes the behaviour: >>> >>> https://www.sqlite.org/pragma.html#pragma_locking_mode >> >> But you need an actual SELECT to get a shared lock and an actual >> write operation to lock it exclusively, just starting the transaction >> and ending it does nothing to that effect? Or is my understanding wrong? > > That's the usual case. But "BEGIN EXCLUSIVE" actually does take an > exclusive lock: > > https://www.sqlite.org/lang_transaction.html
Goodness... Where was my mind?! Thank you Dan and apologies for the round trip, and for misleading the OP! BEGIN EXCLUSIVE will of course instill the lock immediately.
