Check NULL or BLANK values in Oracle Table

Question

Hi All,
I have a column which does not have have any value ( Datatype is Char for that column).
I need query which gets update all the records for which the particular column does not have any value..
UPDATE table name SET COL1='ABC' WHERE ITEM LIKE(' ') OR ITEM IS NULL AND EMPID=10001;
i also tried with other syntax item is not null it was not working updating the records .......
Thanks
Ananda
whether this syntax is correct.........

Answer 1

Hi All,
I have a column which does not have have any value (
Datatype is Char for that column).
I need query which gets update all the records for
which the particular column does not have any
value..
UPDATE table name SET COL1='ABC' WHERE ITEM LIKE(' ')
OR ITEM IS NULL AND EMPID=10001;
i also tried with other syntax item is not null it
was not working updating the records .......
Thanks
Ananda
whether this syntax is correct.........What "other syntax item"?
First, just for sanity, whenever you mix 'and' and 'or' logic, it helps to use parentheses to clarify the order of logic, even if you think you understand how it will be applied by default:
WHERE ITEM LIKE(' ') OR ITEM IS NULL AND EMPID=10001;
WHERE (ITEM LIKE(' ') OR ITEM IS NULL) AND EMPID=10001;
WHERE ITEM LIKE(' ') OR (ITEM IS NULL AND EMPID=10001);
Second, the argument for LIKE should always include the wild-card. Some earlier versions of Oracle treated "LIKE ('xyz')" the same as "LIKE ('xyz%')", leading developers to believe that the wild-card was assumed by default. This was actually a bug corrected in later versions.
Also about LIKE, what do you expect your statement to return if a row has ITEM=' xyz' ?
Address those two issues and see if you still have a problem.