Използвайте join за това.
DELETE T1 -- Make sure only include T1 here.
FROM tb_allinc_sin_trace T1
INNER JOIN tb_outdoors T2 ON T1.confirmation_number = T2. confirmacion_nro
WHERE T1.dates = T2.servicio_fecha;
За да проверите кои записи ще бъдат изтрити, можете да използвате оператор select.
SELECT *
FROM tb_allinc_sin_trace T1
INNER JOIN tb_outdoors T2 ON T1.confirmation_number = T2. confirmacion_nro
WHERE T1.dates = T2.servicio_fecha;
Справка: