How to join two tables with different numbers of rows

I've already search the net about this but it can't solve my problem.

I have two tables one with 10 rows and other with 9 rows

table 1

RNUM       JOB_ID
---------- ---------- 
1          AC_ACCOUNT 
2          AC_MGR 
3          AD_ASST 
4          AD_PRES 
5          AD_VP 
6          FI_ACCOUNT 
7          FI_MGR 
8          HR_REP 
9          IT_PROG 
10         MK_MAN

table 2

RNUM       JOB_ID 
---------- ---------- 
1          AC_ACCOUNT 
2          AC_MGR 
3          AD_ASST 
4          AD_PRES 
5          AD_VP 
6          FI_ACCOUNT 
7          FI_MGR 
8          HR_REP 
9          IT_PROG

I want to join these two tables but I want the output to be like this

RNUM       JOB_ID            RNUM       JOB_ID 
---------- ----------        ---------- ---------- 
1          AC_ACCOUNT        null       null 
2          AC_MGR            1          AC_ACCOUNT 
3          AD_ASST           2          AC_MGR 
4          AD_PRES           3          AD_ASST 
5          AD_VP             4          AD_PRES 
6          FI_ACCOUNT        5          AD_VP 
7          FI_MGR            6          FI_ACCOUNT 
8          HR_REP            7          FI_MGR 
9          IT_PROG           8          HR_REP 
10         MK_MAN            9          IT_PROG

my first code is

select a.*, b.* 
from samp a, samp2 b where a.rnum = b.rnum(+)

but the result of my code is

```
RNUM JOB_ID RNUM JOB_ID
---------- ---------- ---------- ----------
1 AC_ACCOUNT 1 AC_ACCOUNT
2 AC_MGR 2 AC_MGR
3 AD_ASST 3 AD_ASST
4 AD_PRES 4 AD_PRES
5 AD_VP 5 AD_VP
6 FI_ACCOUNT 6 FI_ACCOUNT
7 FI_MGR 7 FI_MGR
8 HR_REP 8 HR_REP
9 IT_PROG 9

When joining you join one key to another x=y but you seem to want to join x=y-1 instead. In your case you want to join 1 with 0 and 2 with 1. This is not a good practice. When joining you always you should join keys with eachother without chaning them.

You should think about what you really want as a result because it is not a logical join to do. But to genereate the result you want you can do like this:

select a.*, b.* from t1 a LEFT OUTER JOIN t2 b on a.rnum-1 = b.rnum

DB Fiddle

This is a good reference image for future use:

StackExchange Database Administrators Q#183359, answer score: 2