Answer Posted / saraswathi muthuraman

Compost key :

More than one column will be used to create compst key

SQL> create table ts_250 (a number,b number,c number,
primary key(a,c));

Table created.

here column A and column C is used to create compst key.
U can't insert null value in both columns.
Only unique combination of column A and column B value can
be inserted.

Primary key :

Key will be created on a single column in table.

SQL> create table ts_251 (a number,b number,c number,
primary key(a));

Table created.


null value cann't be inserted into column a.
oracle will create a index
only unique value can be inserted into column a.
only one primary key can be created on a table

How can I create table in mysql?

1086

---

Is oracle mysql free?

932

---

How to drop an existing view in mysql?

966

---

How does php communicate with mysql?

955

---

What is difference between pdo and mysqli?

1037

---

How can you see all indexes defined for a table?

1156

---

What are the technical specifications of mysql?

1208

---

1)for snapshot replication which agents used? 2)for Transcation replication which agents used? 3)for merge replciation which agents used?

2053

---

What are the benefits of mysql?

982

---

How do I create a new database in mysql?

956

---

How do you connect MySQL database with PHP?

1037

---

can you tell what are the different set operations available in mysql? : Mysql dba

940

---

What is the use of innodb in mysql?

1039

---

What is the date format in mysql?

945

---

How to delete a trigger in mysql?

980

---