Answer Posted / koteswara rao.k

suppose you have landline and through the landline you have
taken net connection .
so at the end of the month you will get two bills on the
landline which is subject to one means

primary key is landline which is parent one ( customer
code available)
broadband and landline ( two bills generation ) are the
unique keys called child keys .(contract ids available)
so in this scenario contract ids can be null but cannot be
duplicate .
One more You cannot remove the primary key until and unless
remove the branched ones.

I have good knowledge on GSM /broadband/pstn technologies .
Any wrong ping with me pls koteswara.9.rao@gmail.com

What is the difference between a user and a schema in oracle?

1029

---

What is where clause in oracle?

1024

---

How to create tables for odbc connection testing?

1110

---

What is rowid and rownum in oracle?

1007

---

Why does for update in oracle 8 cause an ora-01002 error?

999

---

How to generate query output in html format?

1114

---

Can we insert data in view oracle?

1015

---

What are the different editions of oracle?

1105

---

How to drop a tablespace?

1043

---

How do you tell what your machine name is and what is its IP address?

2094

---

What is a initialization parameter file in oracle?

1035

---

How to write a left outer join with the where clause in oracle?

1082

---

How to convert dates to characters in oracle?

1040

---

What is oracle analytical function?

1136

---

How to change system global area (sga) in oracle?

1004

---