Go Oracle Execution string

Declare v_out    varchar2 (a); begin     Execute ' Select P_guid from C_itcomp   '    into    v_out;     Dbms_output.put_line (v_out); End;

Database version must be > =oracle 8i

The direct SELECT statement is useless, guess because select returns multiple rows and columns
can perform DML,DDL, etc.
such as INSERT, UPDATE, CREATE, etc.
You can also bind variables
such as strsql:= ' UPDATE tname SET col1=:variable1 WHERE colx=:variable2 ';
Excute IMMEDIATE strSQL USING value1,value2;

This article was reproduced from: http://blog.sina.com.cn/s/blog_5421dfd20100r29j.html

Executes a dynamic SQL statement or a PL/SQL block that is not created at runtime. Dynamically create and Execute SQL statements

EXECUTE IMMEDIATE--usage examples

1. Running DDL statements in PL/SQL

Begin
   Execute immediate ' set role all ';
End

2. Passing a value to a dynamic statement (USING clause)

Declare
   L_depnam varchar2 (): = ' testing ';
   L_loc     Varchar2 (Ten): = ' Dubai ';
   Begin
   Execute immediate ' INSERT INTO Dept values   (: 1,: 2,: 3) '
     Using, L_depnam, L_loc;
   Commit
End

3. Retrieving values from dynamic statements (INTO clause)

Declare
   l_cnt     varchar2 (20);
Begin
   Execute immediate ' SELECT COUNT (1) from EMP '
     into l_cnt;
   Dbms_output.put_line (L_CNT);
End

Go Oracle Execution string