PL/SQL compilation error with declaring variable - oracle

Question

I am trying to create a basic PL/SQL query where I am using a certain SKU as a parameter so that I can reference it without typing in the sku each time.
When compiling my code I get the error:
Error report:
ORA-06550: line 6, column 1:
PLS-00428: an INTO clause is expected in this SELECT statement
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action:
Here is my code:
declare
myitem number (20);
begin
myitem := 1000956;
select f.order_no
from fdt_maptool f
where f.item = myitem;
end;
/
I thought that maybe it had to do with me using VARCHAR(20) instead of NUMBER, So I tried that as well.
declare
myitem number;
begin
myitem := 1000956;
select f.order_no
from fdt_maptool f
where f.item = myitem;
end;
/
And then received this error:
Error report:
ORA-06550: line 6, column 1:
PLS-00428: an INTO clause is expected in this SELECT statement
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action:
I am fairly new to PL/SQL so if please go easy on me!

Answer 1

Within PLSQL you need to select into
declare
myitem number(20);
myorder number(20);
begin
myitem := 1000956;
select f.order_no
into myorder
from fdt_maptool f
where f.item = myitem;
end;
/
Now there's two standard things that might go wrong. You may not find a record or you may find more than one record. You need exception handlers to handle these cases.
declare
myitem number(20);
myorder number(20);
begin
myitem := 1000956;
select f.order_no
into myorder
from fdt_maptool f
where f.item = myitem;
exception
when no_data_found then
dbms_output.put_line('No record with this ID');
-- Only needed when not selecting a unique column.
when too_many_rows then
dbms_output.put_line('More than one record with this ID');
end;
/
Note that the too_many_rows exception is usually already covered by the fact that you are selecting an ID column that has a unique constraint defined on it.