>>>Hi everybody,
>>>
>>>I am struggling to create one SQL select that will create a query as following (simplified):
>>>
>>>

>>>1. table mytable1 has the following records:
>>>
>>>PK_VAL
>>>1
>>>2
>>>3
>>>
>>>2. table mytable2 has the following records:
>>>PK_VAL
>>>1
>>>2
>>>5
>>>6
>>>

>>>
>>>I want to create a query of all records in mytable1 plus records in mytable2 that have PKs missing in mytable1. In the example above, the resulting query would have the following records:
>>>

>>>PK_VAL
>>>1  (from mytable1)
>>>2  (from mytable1)
>>>3  (from mytable1)
>>>5  (from mytable2)
>>>6  (from mytable2).
>>>

>>>
>>>Thank you in advance for any help.
>>

>>select nvl(MyTble1.PK,myTble2.PK) as PK from myTable1
>>right join myTable2 on myTable1.PK = myTable2.PK

>
>Thank you. I will give it a try.

Or you can switch table 2 and 1 and use a left join. E.g. select

nvl(myTable1.PK, myTable2.PK) as PK from myTable2 left join myTable1 ...

You can also always use FULL OUTER JOIN.