If in a table, for gender column the males are marked as F and the females are marked as M by mistake. In one query how can we replace and correct this problem.

Answer 1

You can use case function.
Here is the query :
Update table_name set gender=(case gender when 'M' then 'F' else 'M' end) ;

Answer 2

Is there any way to do it with replace function ?

Answer 3

In replace function you can change only one value of a single column if you use this column using comma once again it will show an error of duplicate column name, you can't alternate the record at a time