read array of "n" elements from user input - plsql

Question

How to read array of n elements dynamically and display the elements in plsql.
Below is my code (i am new to plsql programming)
set serveroutput on
set verify on
declare
type myarray is table of number index by binary_integer;
x myarray;
i pls_integer;
n number;
begin
-- populate array
dbms_output.put_line('Enter number of array elements');
n := &n;
dbms_output.put_line('Enter elements one by one');
for i in 1..n loop
dbms_output.get_lines(&&x(i),n);
end loop;
i :=0;
-- print array
loop
i := i + 1;
begin
dbms_output.put_line(x(i));
exception
when no_data_found then exit;
end;
end loop;
end;
/
quit;

Answer 1

I stumble into the same issue and wanted to try something.
You could do this with a brutal approach that consists in using you shell to call the client (i.e. sqlplus) any time you want to add a value to your array. I wrote a little package that stores the values of the array in a table. Then you can change the way you store the values, but principle would remain the same:
-- this package uses "execute immediate" statements for everything
-- because it assumes the temporary table T_MY_ARRAY can be non-existent.
create or replace package my_array
authid current_user
is
TYPE a_TBL_Number IS TABLE OF Number INDEX BY BINARY_INTEGER;
procedure init;
procedure add(v in number);
procedure display;
function to_var return a_TBL_Number;
end my_array;
/
create or replace package body my_array
is
procedure init is
-- create table if needed, then make sure its empty;
begin
begin
execute immediate 'create table T_MY_ARRAY(c1 number)';
exception when others then
-- dbms_output.put_line(sqlerrm);
-- we're never sure the temp. table already exists. So create it and catch if existing.
null;
end;
execute immediate 'truncate table T_MY_ARRAY';
end init;
procedure add(v in number) is
-- add new value
begin
execute immediate 'insert into T_MY_ARRAY (c1) values ('||v||')';
end add;
function to_var return a_TBL_Number is
-- hand out an array with the values
t_TBL_n a_TBL_Number;
begin
execute immediate 'select c1 from T_MY_ARRAY ' bulk collect into t_TBL_n;
return t_TBL_n;
end to_var;
procedure display is
t_TBL_n a_TBL_Number;
begin
t_TBL_n:=my_array.to_var();
for i in 1..t_TBL_n.count loop
dbms_output.put_line(t_TBL_n(i));
end loop;
end display;
end my_array;
/
Then here is how you could call this from a shell (here it is for an old ksh):
read SQL_CONNECT?"Enter your SQL connection string:"
read n?"Enter number of array elements:"
# first initialize the array:
sqlplus -s ${SQL_CONNECT} <<_EOF
set serveroutput off
set termout off
set feedback off
begin
my_array.init;
end;
/
_EOF
# then loop on the given number of elements
typeset -i10 i=0
while [[ ${i} -lt ${n} ]]
do
i=i+1
echo iter:${i}
read MY_VALUE?"Enter elements one by one:"
sqlplus -s ${SQL_CONNECT} <<_EOF
set serveroutput off
set termout off
set feedback off
begin
my_array.add(${MY_VALUE});
end;
/
commit;
_EOF
done
# at the end, use stored values to display result:
sqlplus -s ${SQL_CONNECT} <<_EOF
set serveroutput on
set feedback off
begin
dbms_output.put_line('---------------');
dbms_output.put_line('your input was:');
my_array.display;
end;
/
_EOF