Returns information about whether or not a lock can be granted on a particular application resource for a specified lock owner without acquiring the lock. APPLOCK_TEST is an application lock function, and it operates on the current database. The scope of application locks is the database.
Applies to: SQL Server (SQL Server 2008 through current version), Azure SQL Database.
Is the user, role, or application role that can be granted permissions to objects in the database. The caller of the function must be a member of database_principal, dbo, or the db_owner fixed database role in order to call the function successfully.
Is a lock resource name specified by the client application. The application must ensure that the resource is unique. The specified name is hashed internally into a value that can be stored in the SQL Server lock manager. resource_nameis nvarchar(255) with no default. resource_name is binary compared and is case-sensitive, regardless of the collation settings of the current database.
Is the lock mode to be obtained for a particular resource. lock_mode is nvarchar(32) and has no default value. The value can be any of the following: Shared, Update, IntentShared, IntentExclusive, Exclusive.
Is the owner of the lock, which is the lock_owner value when the lock was requested. lock_owner is nvarchar(32). The value can be Transaction (the default) or Session. If default or Transaction is explicitly specified, APPLOCK_TEST must be executed from within a transaction.
DECLARE @result int;
SELECT APPLOCK_MODE('public', 'Form1', 'Transaction');