Select ifnull(10,20) What will be the output?

Answer:

Output will be 10. Actually IfNull works same as IsNull.But Both functions are in different DB as IsNull is in Sql-Server,but IfNull is in MYSql DB.

IfNull returns 1st expression value if the 1st expression value is not null otherwise it returns 2nd expression value.
Here,1st expression value is not null i.e. it's 10 so ifnull will return 10.