Using SQLite

Name

lock_status — Display lock state of each database

Common Usage

PRAGMA lock_status;

Description

The lock_status pragma lists all of the databases in a connection and their current lock status. The result set will contain one row for each attached database.

Column name	Column type	Meaning
database	Text	Database name
status	Text	Lock status

The following locking states may be indicated:

Value	Meaning
unlocked	Database has no locks
shared	Database has a shared read lock
reserved	Database has the reserved write-enable lock
pending	Database has the pending write-enable lock
exclusive	Database has the exclusive write lock
closed	Database file is not open
unknown	Lock state is not known

The first five states correspond to the standard locks SQLite uses to maintain read and write transactions. The closed value is normally returned when a brand new database file has been created, but it has not yet been initialized. Since the locking is done through the filesystem, any database that does not have an associated file will return unknown. This includes both in-memory databases, as well as some temporary databases.

SQLite must be compiled with the SQLITE_DEBUG directive for this pragma to be included.

This is an undocumented pragma.

See Also

schema_version, journal_mode, journal_size_limit, ATTACH DATABASE [SQL Cmd, Ap C], DETACH DATABASE [SQL Cmd, Ap C]