Hi experts,
I am working on Oracle 11 g DB.I am trying to understand diff between NULL and CAST (NULL AS VARCHAR2(10);
So, does this mean, that in SQL '' is always NULL whereas in PL/SQL '' might not be NULL ?
I have a scenario where
I am creating a table using CTASk
1.create table B as select column1,column2,....columns10 from A.
2. Now i am inserting data from B to C using INSERT statement.
Out of 10 feilds few are VARCHAR, NUM and DATE which has data coming from table A.
Now while creating table B out of 10 fields say suppose 7 fields i have to carry NULL data and going forward that NULL values will move to table C.
Is there any difference if i assign the 7 feilds just to NULL in select statement instead CAST (NULL AS VARCHAR2(10);.
Thanks,
S