Answer Posted / ibrahim

PRIMARY KEY is identity of each row. UNIQUE KEY also
identity of each row.
PRIMARY KEY not accepts null values but unique can accept null.

but the core different between primary key and unique is we use primary key to link tow tables with each other but we can not use unique key to do this.

Explain about achiever in sql?

982

---

what is the difference between functional dependecy and multilevel dependency?

2425

---

What is merge statement used for?

978

---

How to view all columns in an existing table?

880

---

What is the difference between PFILE and SPFILE in Oracle?

1002

---

HI Friends Myself Manoj,i am from bengaluru.i have 1 yr of exp in PLSQL but not upto the mark..now attending interviews but m not able to clear even 1 round..i have attended 3 interviews till today.purpose of writing this query is,i want to know the intreview topics that interviewer going to ask frequently,mainly SCENARIO based questions.IF anybody have any PLSQL projects please give it to me,it will helps me alot.Thanks for your patience.

1382

---

What is blob data type in oracle?

1055

---

Is a rollback possible to any savepoint?

1015

---

What is transport network substrate (tns) in oracle?

1001

---

hello friends Im doing my final year engineering in B.Tech.. one of uncle said he can provide job in his company if im good in database management. but i have only basic knowledge about database, so like to join database management course in good intuition. so friends kindly help me to get good intuition because its my future.

2210

---

Explain the use of record length option in exp command.

1033

---

How to insert a record into a table?

1029

---

How to get execution statistics reports on query statements?

1017

---

Explain alias?

1088

---

How to drop a tablespace?

997

---