Answer / esakkiraja

Both of these are substitution variable adn difference
between & and &&:

&--->the variable prefixed with an ampersand (&) to
prompt the user for a value.

eg:
SELECT employee_id, last_name, salary, department_id
FROM employees
WHERE employee_id = &employee_num ;

It should prompt the user to enter a value for employee_num


&&--->Mainly we used the double-ampersand (&&) if you want
to reuse the variable value without prompting the user each
time.

eg:SELECT employee_id, last_name, job_id, &&column_name
FROM employees
ORDER BY &column_name;

Here the user is asked to give the value for variable
column_name only once. The
value supplied by the user (department_id) is used both for
display and ordering of data.

Answer / fahad

&-it is used in run time.it ask d value as new and old value
&&-it repeats the duplicacy and it repeat d same output..
ex.single ampersent...
select employee_id,last_name,hire_date,salary from employees
where department_id=&department_id;
when u enter dis statement.
in output it vil ask d value..
enter value for department_id=



query for &&..
select employee_id,last_name,hire_date,salary from employees
where department_id=&&department_id;

Give two methods you could use to determine what DDL changes have been made.

1 Answers  

---

Explain the use of table functions.

0 Answers  

---

How to update the simple views?give me example?if the table having 100 records and created a view on this table. if i can update the table then how to update the views

2 Answers   Cap Gemini, Syntel,

---

How would you go about generating an EXPLAIN plan?

1 Answers   Satyam,

---

Describe what redo logs are.

1 Answers  

---

How to clone the database using RMAN back

0 Answers  

---

What is the Symbol use for Inner Join

1 Answers   Oracle, TCS,

---

What do you mean by Oracle MEDIA RECOVERY?

0 Answers  

---

What background process refreshes materialized views?

1 Answers  

---

Give the two types of tables involved in producing a star schema and the type of data they hold.

1 Answers  

---

hi iam looking for HRMS(functional) training inst or person in hyderbad. plz help me its urgent

1 Answers  

---

Where would you look for errors from the database engine?

2 Answers   Fintellix,

---