Bind Variable Example
uNo direct limit on the number of bind variables
uLike any other variables, they could be IN (default), OUT, IN/OUT
u
udeclare
u    a NUMBER;
u    b NUMBER:=1;
u    c NUMBER:=2;
u    v_plsql_tx VARCHAR2(2000);
ubegin
u    v_plsql_tx:='begin :v01:=:v02+:v03; end;';
u    execute immediate v_plsql_tx
u    using out a, b, c;
u    DBMS_OUTPUT.put_line('a='||a);
uend;