What does “select count(1) from tab” result?

10 Answers   IBM,

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What are the rules to be applied to nulls whilst doing comparisons?

0 Answers  

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What is a nested table in word?

0 Answers  

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How do we use distinct statement? What is its use?

0 Answers  

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What are sql queries used for?

0 Answers  

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what is External tables? explain with examples

2 Answers   TCS,

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How to write pl sql program in mysql command prompt?

0 Answers  

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What is sql comments?

0 Answers  

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how will be date change into string

4 Answers  

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What is AUTH_ID and AUTH_USER in pl/sql ?

0 Answers   INDUS,

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how to check the 3rd max salary from an employee table? One of the queries used is as follows: select sal from emp a where 3=(select count(distinct(sal)) from emp b where a.sal<=b.sal). Here in the sub query "select count(distinct(sal)) from emp b where a.sal<=b.sal" or "select count(distinct(sal)) from emp b where a.sal=b.sal" should reveal the same number of rows is in't it? Can any one here please explain me how is this query working perfectly. However, there is another query to get the 3rd highest of salaries of employees that logic I can understand. Pls find the query below. "select min(salary) from emp where salary in(select distinct top 3 salary from emp order by salary desc)" Please explain me how "select sal from emp a where 3=(select count(distinct(sal)) from emp b where a.sal<=b.sal)" works source:http://www.allinterview.com/showanswers/33264.html. Thanks in advance Regards, Karthik.

4 Answers  

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how to give permission to users that users can update/insert/delete on a row of table on timeing 10am to 6pm only?

4 Answers   TCS,

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