Sql-server – split a row into multiple rows in sql server according to a specific column

sql server

I have table a having fields id,val and identical table b having fields id,val.

when i am writing an inner join for different data in rows

SELECT * FROM a left join b on a.id = b.id WHERE ( a.id != b.id or
a.val != b.val)

i am getting like below

i want to split this table row into two rows. Help me to write a query to split this data and getting an output table like below

Help!

Best Answer

You can generate the extra row(s) by doing an unpivot using a cross apply and the table value constructor.

select c.id,
       c.val
from dbo.a 
  inner join dbo.b
    on a.id = b.id
  cross apply (values(a.id, a.val),
                     (b.id, b.val)) as c(id, val)
where a.val <> b.val;

Related Solutions

Sql-server – Select multiple rows from one row based on column values

I'd use UNPIVOT for this unless abr and ubr are both indexed and a relatively low proportion contain the value 1.

(Borrowing JNK's table variable)

SELECT id,
       Edition
FROM @prod
UNPIVOT (V FOR Edition IN (abr,ubr)) AS Unpvt
WHERE V = 1

Sql-server – Combine column from multiple rows into single row

This is relatively trivial to do with a correlated subquery. You can't use the COALESCE method highlighted in the blog post you mention unless you extract that to a user-defined function (or unless you only want to return one row at a time). Here is how I typically do this:

DECLARE @x TABLE 
(
  id INT, 
  row_num INT, 
  customer_code VARCHAR(32), 
  comments VARCHAR(32)
);

INSERT @x SELECT 1,1,'Dilbert','Hard'
UNION ALL SELECT 1,2,'Dilbert','Worker'
UNION ALL SELECT 2,1,'Wally','Lazy';

SELECT id, customer_code, comments = STUFF((SELECT ' ' + comments 
    FROM @x AS x2 WHERE id = x.id
     ORDER BY row_num
     FOR XML PATH('')), 1, 1, '')
FROM @x AS x
GROUP BY id, customer_code
ORDER BY id;

If you have a case where the data in comments could contain unsafe-for-XML characters (>, <, &), you should change this:

     FOR XML PATH('')), 1, 1, '')

To this more elaborate approach:

     FOR XML PATH(''), TYPE).value(N'(./text())[1]', N'varchar(max)'), 1, 1, '')

(Be sure to use the right destination data type, varchar or nvarchar, and the right length, and prefix all string literals with N if using nvarchar.)

Best Answer

Related Solutions

Sql-server – Select multiple rows from one row based on column values

Sql-server – Combine column from multiple rows into single row

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