what is the output of the query select * from emp where 1=2
Answers were Sorted based on User's Feedback
Answer / mithun
hi everyone ,
its a trick to copy the structure of the table wthout the
data .
1 SQL> create table employee1
2 as select * from emp
3 where 1=2;
the compiler will look for the statment 2 first
then it will come to the 3 line to check the condition ,when
it gets a 0 [means false] at that time only the table
structure was there in the buffer ; now it will return to
the 1st statement to create a table with the structure only .
so it will return only the structure of the table .
similarly when this
SELET *
FROM EMP
WHERE 1=2;
querry is executed as per the false conditon it will only
show no rows selected .
hope you get the answer .
have a nice time for any more assistance you can mail me to
ermithun.c@gmail.com
| Is This Answer Correct ? | 27 Yes | 2 No |
Answer / arun
Since we are using SELECT statement for this query,
We can view only the structure of the table. where as if we
use the create query we can copy the structure of the table.
| Is This Answer Correct ? | 24 Yes | 6 No |
Answer / anfal
Hi
When i tried the below query in oracle9i it says no rows
selected. could you please let us know in which version of
Oracle u tried this query.
SQL> select * from emp where 1=2;
no rows selected
| Is This Answer Correct ? | 17 Yes | 2 No |
Answer / ganesh
for sure it will display no rows selected
coz for select * from emp give all and because of the where
clause 1=2.......no point in time 1 is eual to 2 or 2 is
equal to 1....so it returns no row.
eg 1=2 ----give no rows
1=1 ---gives all rows
come out of oracle and think as simple logic (is 1=2)....if
yes true else false.....similar of oracle also
| Is This Answer Correct ? | 12 Yes | 2 No |
Answer / vijay amresh
Hi
When i tried the below query in oracle9i it says no rows
SELET *
FROM EMP
WHERE 1=2;
gives the query for 1=2, it is false so There is no row.
But if it runs for 1=1, then all rows are selected.
| Is This Answer Correct ? | 9 Yes | 1 No |
Answer / suresh kumar somayajula
Hi Anfal,
Try the following Query.
SQL> CREATE TABLE EMP_NEW
AS
SELET *
FROM EMP
WHERE 1=2;
Table Created
SQL> SELECT * FROM EMP_NEW
no rows selected.
SQL> DESC EMP_NEW;
Structure will be displayed.
Please correct me if any mistakes.
Thank you,
Suresh
| Is This Answer Correct ? | 11 Yes | 4 No |
Answer / vikas patil
It is used only for condition checking
for example select * From emp Where 1=2;
it will return 0 rows
select * From emp Where 1=1;
it will return all rows
select * From emp Where 1<2;
it will return all rows
select * From emp Where 1<=1;
it will return all rows
| Is This Answer Correct ? | 2 Yes | 0 No |
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