@@TRANCOUNT - SQL SERVER

Returns the number of BEGIN TRANSACTION statements that have occurred on the current connection.

The BEGIN TRANSACTION statement increments @@TRANCOUNT by 1. ROLLBACK TRANSACTION decrements @@TRANCOUNT to 0, except for ROLLBACK TRANSACTION savepoint_name, which does not affect @@TRANCOUNT. COMMIT TRANSACTION or COMMIT WORK decrement @@TRANCOUNT by 1.

PRINT @@TRANCOUNT
--  The BEGIN TRAN statement will increment the
--  transaction count by 1.
BEGIN TRAN
    PRINT @@TRANCOUNT
    BEGIN TRAN
        PRINT @@TRANCOUNT
--  The COMMIT statement will decrement the transaction count by 1.
    COMMIT
    PRINT @@TRANCOUNT
COMMIT
PRINT @@TRANCOUNT