Explain the concept of the DUAL table.
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Answer / saraswathi muthuraman
Oracle will have a default table called 'DUAL'.
Dual table will have only one column "DUMMY". U cann't
insert values into dual table. By default, a row will
existing in dual table.
SQL> desc dual;
DUMMY varchar2(1)
SQL> select * from dual;
X
1 row selected.
SQL> insert into dual values (10);
insert into dual values (10)
*
ERROR at line 1:
ORA-01031: insufficient privileges
U can create you own table with the name of dual.
SQL> create table dual(xy number,zz number);
Table created.
SQL> desc dual;
xy number
zz number
u can insert values in you own dual table.
Is This Answer Correct ? | 4 Yes | 0 No |
Answer / eshwari
Dual table is a sample permanent table which come along with
oracle.
for example if u want to knw the sin(45) value then u have
to retreave it from a table.but there is no table to
retreave that value.
so we use the sample table dual as table name in place of
table name in the select query.
ex:select sin(45) from dual;
Is This Answer Correct ? | 4 Yes | 0 No |
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