mysql venstre ydre joinforbindelse

Du filtrerer tc_date_transaction, som filtrerer alle null-værdier i dette felt, selv dem, der genereres af den ydre-join, og derfor besejrer dens formål. Flyt filteret "tc_date_transaction ="17/06/2010"" ind i join-klausulen, og det vil virke.

SELECT * 
  FROM employee LEFT OUTER JOIN timecard 
       ON employee.employee_id = timecard.employee_id and tc_date_transaction = "17/06/2010";

eller skriv

SELECT * 
  FROM employee LEFT OUTER JOIN timecard 
       ON employee.employee_id = timecard.employee_id 
  where (tc_date_transaction = "17/06/2010" or tc_date_transaction is null);