select query to push null values to last column in address lines - sql

Question

I need to write a query to select the address lines so that the null values should be pushed to last columns. For example if the table has below data
ID, line1, line2, line3, line4, line5, line6
1 null test2 test3 test4 test5 test6
2 test1 test2 test3 test4 test5 test6
3 null null null null test5 test6
4 test1 test2 test3 null test5 test6
Output of the query should be as follow
ID, line1, line2, line3, line4, line5, line6
1 test2 test3 test4 test5 test6 null
2 test1 test2 test3 test4 test5 test6
3 test5 test6 null null null null
4 test1 test2 test3 test5 test6 null
I tried to concatenate the values with a delimiter by eliminating the nulls and then split the values again, but I am having difficulty in splitting the values back as the actual data contains characters which are not xml supported. Is there a easy way to do this with out creating functions to split? Below works when there are no characters in values which cause cast to xml fail
SELECT
ISNULL(Line1 + '|', '')
+ ISNULL(Line2 + '|', '')
+ ISNULL(Line3 + '|', '')
+ ISNULL(Line4 + '|', '')
+ ISNULL(Line5 + '|', '')
+ ISNULL(Line6 , '') as tmpaddr
FROM #addr1
SELECT DISTINCT id,
S.a.value('(/H/r)[1]', 'VARCHAR(100)') AS line1,
S.a.value('(/H/r)[2]', 'VARCHAR(100)') AS line2,
S.a.value('(/H/r)[3]', 'VARCHAR(100)') AS line3,
S.a.value('(/H/r)[4]', 'VARCHAR(100)') AS line4,
S.a.value('(/H/r)[5]', 'VARCHAR(100)') AS line5,
S.a.value('(/H/r)[6]', 'VARCHAR(100)') AS line6
FROM
(
SELECT *,CAST (N'<H><r>' + REPLACE(tmpaddr , '|', '</r><r>') + '</r></H>' AS XML) AS [vals]
FROM #addr ) d
CROSS APPLY d.[vals].nodes('/H/r') S(a)

Answer 1

Let me assume you are using SQL Server, based on the syntax conventions.
You can do what you want with cross apply and aggregation:
SELECT a.id, t.*
FROM #addr1 a CROSS APPLY
(SELECT MAX(CASE WHEN seqnum = 1 THEN line END) as line1,
MAX(CASE WHEN seqnum = 2 THEN line END) as line2,
MAX(CASE WHEN seqnum = 3 THEN line END) as line3,
MAX(CASE WHEN seqnum = 4 THEN line END) as line4,
MAX(CASE WHEN seqnum = 5 THEN line END) as line5,
MAX(CASE WHEN seqnum = 6 THEN line END) as line6
FROM (SELECT num, line, ROW_NUMBER() OVER (ORDER BY num) as seqnum
FROM (VALUES (1, a.line1),
(2, a.line2),
(3, a.line3),
(4, a.line4),
(5, a.line5),
(6, a.line6)
) v(num, line)
WHERE line IS NOT NULL
) t
) t;