Difference between queries please 1

[kishorecvr]

Can any one give me the difference between the following queries please....

SELECT * FROM employee
WHERE department_id = 30 AND salary < 2850;

SELECT * FROM employee
WHERE salary IN
(SELECT salary FROM employee
WHERE department_id = 30 AND salary < 2850);

 

[frag]

I would say that your first query does the job you want.
The second one does the same but is unlikely complicated and should not ne used.

But if anyone has another opinion about this... let me hear.
Perhaps I am wrong.

cya

frag patrick.metz@epost.de

 

[fluteplr]

I agree the 2nd query is pointlessly complicated and will probably run slower unless the DBMS you are using has an unusually smart query optimizer/

 

[carp]

The second one is completely different.
The first query is constrained to employees in Department 30.
The second query will return records for any employee in the company (regardless of department) that makes the same salary as any employee in Department 30 who is paid less than 2850.

If the second one said &quot;where empno in&quot; instead of &quot;where salary in&quot;, the queries would return the same information.

 

[fluteplr]

You are absolutly correct, that what I get for answering questions before my 1st cup of coffee.