CREATE TABLE table_31319 ("Year" TEXT, "Conductor" TEXT, "Opera House or Orchestra" TEXT, "Label" TEXT, "Countess" TEXT, "Count" TEXT, "Flamand" TEXT, "Olivier" TEXT, "La Roche" TEXT, "Clairon" TEXT)

When dietrich fischer-dieskau is the olivier who is the conductor?
SELECT "Conductor" FROM table_31319 WHERE "Olivier" = 'Dietrich Fischer-Dieskau'
SELECT "Conductor" FROM "table_31319" WHERE "Olivier" = 'Dietrich Fischer-Dieskau'