在数据透视方面需要帮助？

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 |