Answer Posted / sabariesh thavamani

i worked out the coding in the above using oracle 9 i, but
i could not get the correct answer what he told.. try it

SQL> create table sab(name varchar2(10) unique);

Table created.

SQL> insert into sab values('&sab');
Enter value for sab: null
old 1: insert into sab values('&sab')
new 1: insert into sab values('null')

1 row created.

SQL> /
Enter value for sab: null
old 1: insert into sab values('&sab')
new 1: insert into sab values('null')
insert into sab values('null')
*
ERROR at line 1:
ORA-00001: unique constraint (LPUSER18.SYS_C0038068)
violated


SQL> /
Enter value for sab: sabari
old 1: insert into sab values('&sab')
new 1: insert into sab values('sabari')

1 row created.

SQL> /
Enter value for sab: null
old 1: insert into sab values('&sab')
new 1: insert into sab values('null')
insert into sab values('null')
*
ERROR at line 1:
ORA-00001: unique constraint (LPUSER18.SYS_C0038068)
violated


SQL> select * from sab
2 ;

NAME
----------
null
sabari
try it....

Can I create table without primary key?

754

---

What is procedure and function in sql?

765

---

How to get list of all tables from a database?

876

---

Define join and name different types of joins?

740

---

Can dml statements be used in pl/sql?

798

---

What is a system versioned table?

725

---

explain mysql aggregate functions. : Sql dba

752

---

Is primary key a clustered index?

717

---

What is primary key and foreign key?

747

---

what is a constraint? : Sql dba

898

---

How do I send sql query results to excel?

797

---

How do I restart sql?

744

---

what is data control language? : Sql dba

767

---

Difference between table function and pipelined function?

790

---

Is not null in sql?

748

---