sql - Trying to create a variable out of a column argument -

i trying create variable value in sql.

i getting error "exact fetch returns more requested number of rows"

here sql trying run

declare title varchar2(1) := 'n'; begin select title_flag title control.title title_flag=title;   end;

declare title varchar2(1) := 'n'; begin select title_flag title control.title title_flag=title , rownum = 1;   end;

you need use sort of condition 1 row returned query error means getting more 1 record doesn't know assign

Prevent