Interested to Buy Any Domain ? << Click Here >> for more details...
What WHERE CURRENT OF clause does in a cursor?
- 2 Answers
- 4354 Views
- I also Faced
- E-Mail Answers
Answers were Sorted based on User's Feedback
If you want to UPDATE or DELETE record from table by using cursor which is defined from same table,"WHERE CURRENT OF" clause can be used. We have to create cursor with "FOR UPDATE" clause to use above clause.
The most recent record fetched from the table (by looping of cursor records) should be updated or deleted by using "WHERE CURRENT OF". When a cursor open with FOR UPDATE clause ,cursor's active set will have row level Exclusive Lock. Other sessions can query the table records, and not able to delete/update or SELECT with FOR UPDATE clause.
Example: Want to update value for GRADE column to '1' for the student who has Id = '1'.
Declare
cursor C1 is
select st_id, grade,st_last_name from student where st_id = 3;
for update of grade;
[ variable declaration ……] ;
begin
open C1;
fetch C1 into v_id,v_grade,v_name;
if C1%notfound then
dbms_output.put_line (‘No Record is found.’);
else
update student set grade=1 WHERE CURRENT OF;
COMMIT;
END IF;
CLOSE C1;
end;
| Is This Answer Correct ? | 1 Yes | 0 No |
Answer / kamala k n
return latest fetch row to perform DML on it it is unique
| Is This Answer Correct ? | 0 Yes | 0 No |
What is a cursor in oracle?
What is Database Link ?
How can we find out the duplicate values in an oracle table?
What would you do with an in-doubt distributed transaction?
What SQL query from v$session can you run to show how many sessions are logged in as a particular user account?
how to find out largest value in a table
How to use "for" statements in oracle?
How to convert raw data type into text in oracle? Explain
What is an Index ? How it is implemented in Oracle Database ?
what is insert all statement in sql
How to create a table index in oracle?
Explain the use of Merge statement in oracle 11g
Oracle General 
