Question

i’m having a problem with my database. I have the folowing:

create table book
(
    name_b varchaR(50) primary key,
    typee varchaR(50) not null,
    nmbr integer unique not null,
    yeare numeric(4,0) default null,
)

create table story
(
    id integer identity(1,1) primary key,
    name_s varchar(100) not null,
    chars varchar(100) not null,
    code varchaR(200) null,
    artist varchar(100) default null,
    argument varchar(100) default null,
    book_ref_name varchar(50) references book(name_b),
    book_ref_nmbr integer references book(nmbr)
)

insert into story values
('StoryName1','StoryChars1',null,default,default,'BookName1',13),
('StoryName2','StoryChars2',null,default,default,'BookName2',35),
('StoryName3','StoryChars3',null,default,default,'BookName3',125)

insert into book values
('BookName1','Type1',13,default),
('BookName2','Type2',35,default),
('BookName3','Type3',125,default)

what i want with this is the STORY.CODE to be replaced from NULL to a junction of strings for example imagine the first entry of the STORY table

('StoryName1','StoryChars1',null,default,default,'BookName1',13)

in this case i would like the STORY.CODE to be replaced with ‘StoryName1-StoryChars1-BookName1-13’.

is this even possible? if it isn’t whats the nearest possibility of something similar?
thx in advance

---

another doubt i have, how can i make a SELECT statement that selects * from STORY except the null fields. for example if a story has no argumentist/artist i dont want that field to show up.

Answer 1

If you want to do this via an UPDATE

UPDATE story
SET code = name_s + '-' + chars + '-' + book_ref_name + '-' + Convert(varchar(50), book_ref_nmbr)
WHERE code IS NULL

Via an INSERT you basically do something similar:

INSERT INTO story (fields,....)
SELECT 'StoryName1'
    ,'StoryChars1'
    ,IsNull(('StoryName1' + '-' + 'StoryChars1'+ '-' + 'BookName1' + '-' + Convert(varchar(50), 13), codevalue)
    ,default,default,'BookName1',13

Or you can use a CASE

INSERT INTO story (fields,....)
SELECT 'StoryName1'
    ,'StoryChars1'
    , CASE
      WHEN code Is Null
            THEN ('StoryName1' + '-' + 'StoryChars1'+ '-' + 'BookName1' + '-' + Convert(varchar(50), 13)
            ELSE yourcodevalue
      END
    ,default,default,'BookName1',13

As far as your second question regarding the SELECT, I think this is what you need

SELECT *
FROM story
WHERE artist is not Null
AND/OR argument is not Null