View the Exhibit and examine the structure of the ORD table.
Evaluate the following SQL statements that are executed in a user session in the specified order:
CREATE SEQUENCE ord_seq;
SELECT ord_seq.nextval
FROM dual;
INSERT INTO ord
VALUES (ord_seq.CURRVAL, ’25-jan-2007′,101);
UPDATE ord
SET ord_no= ord_seq.NEXTVAL
WHERE cust_id =101;
What would be the outcome of the above statements?
A.
All the statements would execute successfully and the ORD_NO column would contain the value 2 for the CUST_ID 101.
B.
The CREATE SEQUENCE command would not execute because the minimum value and maximum value for the sequence have not been specified.
C.
The CREATE SEQUENCE command would not execute because the starting value of the sequence and the increment value have not been specified.
D.
All the statements would execute successfully and the ORD_NO column would have the value 20 for the CUST_ID 101 because the default CACHE value is 20.
Yes, A.
Whats the default value wid which our sequence will b intialized wid ?
Is it initialized by -1 ??
A is correct.
When sequence is created and we’ll try to retrieve seq_name.CURRVAL we’ll get the error. Firstly we should launch the sequence retrieve seq_name.NEXTVAL and then CURRVAL of that sequence is 1.