Find open transactions in SQL Server

DBCC OPENTRAN;

And this more extreme example (also from docs.microsoft) creates a table of the results....

-- Create the temporary table to accept the results.
CREATE TABLE #OpenTranStatus (
   ActiveTransaction varchar(25),
   Details sql_variant
   );
-- Execute the command, putting the results in the table.
INSERT INTO #OpenTranStatus
   EXEC ('DBCC OPENTRAN WITH TABLERESULTS, NO_INFOMSGS');

-- Display the results.
SELECT * FROM #OpenTranStatus;
GO

Source

• DBCC OPENTRAN (Transact-SQL)