EXECUTE IMMEDIATE — dynamically prepare and execute a statement
EXECUTE IMMEDIATE string
     EXECUTE IMMEDIATE immediately prepares and
     executes a dynamically specified SQL statement, without
     retrieving result rows.
    
string #A literal string or a host variable containing the SQL statement to be executed.
     In typical usage, the string is a host
     variable reference to a string containing a dynamically-constructed
     SQL statement.  The case of a literal string is not very useful;
     you might as well just write the SQL statement directly, without
     the extra typing of EXECUTE IMMEDIATE.
    
     If you do use a literal string, keep in mind that any double quotes
     you might wish to include in the SQL statement must be written as
     octal escapes (\042) not the usual C
     idiom \".  This is because the string is inside
     an EXEC SQL section, so the ECPG lexer parses it
     according to SQL rules not C rules.  Any embedded backslashes will
     later be handled according to C rules; but \"
     causes an immediate syntax error because it is seen as ending the
     literal.
    
     Here is an example that executes an INSERT
     statement using EXECUTE IMMEDIATE and a host
     variable named command:
sprintf(command, "INSERT INTO test (name, amount, letter) VALUES ('db: ''r1''', 1, 'f')");
EXEC SQL EXECUTE IMMEDIATE :command;
     EXECUTE IMMEDIATE is specified in the SQL standard.