Skip to Main Content

SQL & PL/SQL

Announcement

For appeals, questions and feedback about Oracle Forums, please email oracle-forums-moderators_us@oracle.com. Technical questions should be asked in the appropriate category. Thank you!

explain nvl in the not exists

Rajesh123Mar 13 2015 — edited Mar 14 2015

Hi,

I am trying to insert sample_sender to sample_receiver  table

CREATE TABLE sample_sender

  (

     a_id          NUMBER,

     b_id          NUMBER,

     sum_total     NUMBER,

     sum_toatal2   NUMBER,

     code          VARCHAR2(6),

     default_value NUMBER

  );

1)insert into sample_sender values( 10,11,100,120,NULL,NULL);

2)insert into sample_sender values( 10,11,100,120,NULL,1);

4)

CREATE TABLE sample_receiver

  (

     a_id          NUMBER,

     b_id          NUMBER,

     sum_total     NUMBER,

     sum_toatal2   NUMBER,

     code          VARCHAR2(6),

     default_value NUMBER

  );

5)

INSERT INTO sample_receiver

            (

        a_id ,

        b_id ,

        sum_total ,

        sum_toatal2 ,

        code ,

        default_value

            )

SELECT a.a_id ,

       a.b_id ,

       a.sum_total ,

       a.sum_toatal2 ,

       a.code ,

       a.default_value

FROM   sample_sender a

WHERE  NOT EXISTS

       (

          SELECT 1 FRoM sample_receiver b

           WHERE  a.a_id=b.a_id

            AND   a.b_id=b.b_id

        --AND   NVL(a.code,'X')=NVL(b.code,'X')

        --AND   NVL(a.default_value,-1)=NVL(b.default_value,-1)

       );


First i used 1st insert command

so my sample_sender table has 1 row and my sample_receiver  table also 1 row

and again tried to inserted  with 2nd insert command so my sample_sender table has 2 rows and my sample_receiver  table only 1 row that is Exist row

So that's why we can used NVL , But i want to know the how it NVL is working here?


Thanks

Message was edited by: Rajesh123 Added Extra Message

This post has been answered by BrunoVroman on Mar 13 2015
Jump to Answer
Comments
Locked Post
New comments cannot be posted to this locked post.
Post Details
Locked on Apr 11 2015
Added on Mar 13 2015
11 comments
1,992 views