executing `EXECUTE IMMEDIATE ` Oracle Statement Getting Error - oracle

Question

I am NewBie to Oracle. When I Execute Following Statement
BEGIN
EXECUTE IMMEDIATE 'SELECT * FROM DUAL;';
END;
/
I Got Error as
Error starting at line : 2 in command - BEGIN EXECUTE IMMEDIATE
'SELECT * FROM DUAL;'; END;
Error report - ORA-00911: invalid
character ORA-06512: at line 2
00911. 00000 - "invalid character"
*Cause: identifiers may not start with any ASCII character other than
letters and numbers. $#_ are also allowed after the first
character. Identifiers enclosed by doublequotes may contain
any character other than a doublequote. Alternative quotes
(q'#...#') cannot use spaces, tabs, or carriage returns as
delimiters. For all other contexts, consult the SQL Language
Reference Manual.
*Action:

Answer 1

The problem is the ; character in 'SELECT * FROM DUAL;'.
From documentation:
execute_immediate_statement ::=
EXECUTE_IMMEDIATE dynamic_string
{
INTO { define_variable [, define_variable ...] | record_name }
| BULK COLLECT INTO { collection_name [, collection_name ...] | :host_array_name }
}
[ USING [ IN | OUT | IN OUT ] bind_argument
[, [ IN | OUT | IN OUT ] bind_argument] ... ] [ returning_clause ] ;
... where dynamic_string is (emphasis mine):
A string literal, variable, or expression that represents a single SQL
statement or a PL/SQL block. It must be of type CHAR or VARCHAR2, not
NCHAR or NVARCHAR2.
Since it won't accept multiple statements unless you enclose them in a single PL/SQL block, the ; separator is not expected.
There's a better explanation at Using the EXECUTE IMMEDIATE Statement in PL/SQL:
When constructing a single SQL statement in a dynamic string, do not
include a semicolon (;) at the end inside the quotation mark. When
constructing a PL/SQL anonymous block, include the semicolon at the
end of each PL/SQL statement and at the end of the anonymous block;
there will be a semicolon immediately before the end of the string
literal, and another following the closing single quotation mark.

Answer 2

you can fix the error by removing ; from the dynamic query.
BEGIN
EXECUTE IMMEDIATE 'SELECT * FROM DUAL';
END;
/
This query is not going to return any results;
select statement in EXECUTE IMMEDIATE without into clause will be ignored.
Declare
v_variable number;--some variable
BEGIN
EXECUTE IMMEDIATE 'SELECT clmn FROM tbl' into v_variable;
END;
/

Answer 3

Just remove ';' from the dymanic string.Try this :
BEGIN
EXECUTE IMMEDIATE 'SELECT * FROM DUAL';
END;