Terminology question

Question

DB version : 11.2
SQL> desc test123
Name              Null?    Type
MYDATECOL                  DATE
SQL> select * from test123;
MYDATECOL
15-08-2012
16-08-2012
18-08-2012
19-08-2012The following anonymous block is erroring out because the declared variable can hold only 1 value at a time but the SELECT is returning a list of 4 dates. What is the word for these kind of variables (which can hold only one value) in English language ?
declare
myvariable date;
begin
     select MYDATECOL into myvariable from test123;
     dbms_output.put_line ('The date is --> : '||myvariable);
end;
ERROR at line 1:
ORA-01422: exact fetch returns more than requested number of rows
ORA-06512: at line 5

Answer 1

One more question. Why I am getting error for the below code despite creating the right collection type ?
declare
TYPE mytabtype IS TABLE OF date INDEX BY BINARY_INTEGER;
myvariable mytabtype;
begin
        select MYDATECOL into myvariable from test123;
        for i in 1..myvariable.count
        loop
             --dbms_output.put_line ('The date is --> : '||myvariable(i));
             dbms_output.put_line (to_char(myvariable(i)));
        end loop;
end;
ERROR at line 6:
ORA-06550: line 6, column 31:
PLS-00597: expression 'MYVARIABLE' in the INTO list is of wrong type
ORA-06550: line 6, column 42:
PL/SQL: ORA-00904: : invalid identifier
ORA-06550: line 6, column 9:
PL/SQL: SQL Statement ignored