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Question 40: Which of the following queries return 0? – MySQL Question of the Day

Question 40: Which of the following queries return `0`?

8. March 2010

By urs in mysql questions

1 Comment

(Find all correct answers)

a) select count(i)
     from (select 1 as i union select 2 union select null) v1
     where i is null;
 
b) select count(*)
     from (select 1 as i union select 2 union select null) v1
     where i is null;
 
c) select count(*)
     from (select 1 as i union select 2 union select null) v1
     where i <=> null;
 
d) select count(*)
     from (select 1 as i union select 2 union select null) v1
     where i = null;

[ SQL Expressions (15%) - NULL Values ]

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