Long to wide - SQL [duplicate] - sql-server

Question

This question already has answers here:
SQL Server dynamic PIVOT query?
(9 answers)
Closed 6 years ago.
I have a table that is long (for example)
Date Person Number
2015-01-03 A 4
2015-01-04 A 2
2015-01-05 A 3
2015-01-03 B 5
2015-01-04 B 6
2015-01-05 B 7
2015-01-03 C 1
2015-01-04 C 3
2015-01-05 C 4
2015-01-05 D 4
2015-01-04 E 1
2015-01-05 E 3
And I need it to look like (wide):
Date A B C D E
2015-01-03 4 5 1 0 0
2015-01-04 2 6 3 0 1
2015-01-05 3 7 4 4 3
Any help would be much appreciated. I am using Transact. Thanks.

Answer 1

Using PIVOT:
select date, isNull([A], 0) as A,
isNull([B], 0) as B,
isNull([C], 0) as C,
isNull([D], 0) as D,
isNull([E], 0) as E
from
( select date, person, number
from tbl ) AS SourceTable
PIVOT
( max(number) for
Person in ( [A], [B], [C], [D], [E]) ) AS PivotTable;
Dynamic version is:
DECLARE #columns NVARCHAR(MAX), #whereColumns NVARCHAR(MAX), #sql NVARCHAR(MAX);
SET #columns = N'';
SET #whereColumns = N'';
SELECT #columns += N', isNull(p.' + QUOTENAME(Person) +', 0) as ' + Person,
#whereColumns += N', ' +QUOTENAME (Person)
FROM (select Person from tbl group by Person) AS x;
SET #sql = N'
select date, ' + STUFF(#columns, 1, 2, '') +
N'
from
( select date, person, number
from tbl ) AS SourceTable
PIVOT
( max(number) for
Person in ( '
+ stuff(#whereColumns, 1, 2, '')
+ ' )
) AS P '
print #sql;
exec (#sql);

Answer 2

You can use conditional aggregation:
SELECT
Date,
[A] = MAX(CASE WHEN Person = 'A' THEN Number ELSE 0 END),
[B] = MAX(CASE WHEN Person = 'B' THEN Number ELSE 0 END),
[C] = MAX(CASE WHEN Person = 'C' THEN Number ELSE 0 END),
[D] = MAX(CASE WHEN Person = 'D' THEN Number ELSE 0 END),
[E] = MAX(CASE WHEN Person = 'E' THEN Number ELSE 0 END)
FROM #tbl
GROUP BY Date
If you have unknown number of Persons, then you have to do it dynamically:
DECLARE #sql NVARCHAR(MAX) = N'';
SELECT #sql =
'SELECT
Date' + CHAR(10) +
(
SELECT DISTINCT
' , MAX(CASE WHEN Person = ''' + Person + ''' THEN Number ELSE 0 END) AS ' + QUOTENAME(Person) + CHAR(10)
FROM #tbl
FOR XML PATH('')
) +
'FROM #tbl
GROUP BY Date;';
PRINT (#sql);
EXEC (#sql);
ONLINE DEMO