need help in pivoting a data? - sql

Question

First of all, I am new to SQL. Here is the sample (for both table1 and table2, I have created a SNO as primary key and it's also identity column)
Table1:
PID PNAME PartID
--- ----- ------
0 Length 1
1 Breadth 1
2 Height 1
0 Area 2
1 Volume 2
Table2:
SampleID PID Pvalue PartID ModifiedDate Operator
-------- --- ------ ------ ------------ --------
0 0 10 1 10-Mar-14 Test
0 1 10 1 10-Mar-14 Test
0 2 Fail 1 10-Mar-14 Test
1 0 20 1 12-Mar-14 Test
1 1 Fail 1 12-Mar-14 Test
1 2 Fail 1 12-Mar-14 Test
0 0 10 2 13-Mar-14 Test1
0 1 10 2 13-Mar-14 Test1
Depending upon the PartID, I must get the following results
PARTID: 1
PNAME 0 1
------------ --------- ---------
Length 10 20
Breadth 10 Fail
Height Fail Fail
ModifiedDate 10-Mar-14 12-Mar-14
Operator Test Test
PARTID: 2
PNAME 0
------------ ---------
Area 10
Volume 10
ModifiedDate 13-Mar-14
Operator Test1
How to achieve the desired output as mentioned above in SQL Server 2008?

Answer 1

You can use PIVOT to get the result but you will also need to unpivot the ModifiedDate and Operator columns so you can display them in a single column with the PName. Your final result will need a dynamic solution but it would be much easier to write this static first, then convert to dynamic sql.
The basic syntax will be:
select pname, [0], [1]
from
(
select t2.sampleid, pname = c.col, c.value
from table1 t1
inner join table2 t2
on t1.partid = t2.partid
and t1.pid = t2.pid
cross apply
(
select Pname, pvalue union all
select 'ModifiedDate', convert(varchar(10), ModifiedDate, 120) union all
select 'Operator', Operator
) c (col, value)
where t1.partid = 1
) d
pivot
(
max(value)
for sampleid in ([0], [1])
) p;
See SQL Fiddle with Demo. You'll see that I used CROSS APPLY to convert the 3 columns PName, ModifiedDate and Operator into a single column. This is necessary so you can easily get to the values for each SampleId. The above version is a static version meaning you are hard-coding the values for the final columns, but if you want to have this adjust based on the PartId, you will need to use dynamic SQL:
DECLARE #cols AS NVARCHAR(MAX),
#query AS NVARCHAR(MAX),
#partid int,
#paramdef nvarchar(max)
set #partid = 1
set #paramdef = '#partid int'
select #cols = STUFF((SELECT ',' + QUOTENAME(sampleid)
from Table2
where partid = #partid
group by sampleid
order by sampleid
FOR XML PATH(''), TYPE
).value('.', 'NVARCHAR(MAX)')
,1,1,'')
set #query = 'SELECT pname,' + #cols + '
from
(
select t2.sampleid, pname = c.col, c.value
from table1 t1
inner join table2 t2
on t1.partid = t2.partid
and t1.pid = t2.pid
cross apply
(
select Pname, pvalue union all
select ''ModifiedDate'', convert(varchar(10), ModifiedDate, 120) union all
select ''Operator'', Operator
) c (col, value)
where t1.partid = #partid
) x
pivot
(
max(value)
for sampleid in (' + #cols + ')
) p '
exec sp_executesql #query, #paramdef, #partid = #partid;
See SQL Fiddle with Demo. Both give a result:
| PNAME | 0 | 1 |
|--------------|------------|------------|
| Breadth | 10 | Fail |
| Height | Fail | Fail |
| Length | 10 | 20 |
| ModifiedDate | 2014-03-10 | 2014-03-12 |
| Operator | Test | Test |