Pivot sql convert rows to columns

Question

The below query get the following out put.

Service Date  Product1 Product2 
01/Jun/2015    1           3
02/Jun/2015    2           5

Instead o

Answer 1

This is how it's done using plain ANSI SQL.

First, you need to pivot vertically - UNPIVOT in TRANSACT-SQL speak - which you do by CROSS JOINing with a single-column temp table with as many consecutive integers as you have values to "unpivot". You use those integers as indexes in a CASE WHEN expression for the values.

Then, you re-pivot, using a SUM(CASE WHEN ...) expression, and GROUP BY the column whose values you want to see vertically in the first column.

Here goes:

WITH
-- input
input(Service_Date,Product1,Product2) AS (
          SELECT DATE '2015-06-01',1,3
UNION ALL SELECT DATE '2015-06-02',2,5
)          
,
-- start vertical pivot: two integers
two_ints(idx) AS (SELECT 1 UNION ALL SELECT 2)
,
-- vertical pivot: CROSS JOIN input with two integers
vert_pivot AS (
SELECT
  Service_Date
, idx
, 'Product'||CAST(idx AS CHAR(1)) AS product
, CASE idx WHEN 1 THEN Product1 WHEN 2 THEN Product2 END AS qty
FROM input CROSS JOIN two_ints
)
-- debug
-- SELECT * FROM vert_pivot;
-- Service_Date|idx|product |qty
-- 2015-06-01  |  1|Product1|  1
-- 2015-06-01  |  2|Product2|  3
-- 2015-06-02  |  1|Product1|  2
-- 2015-06-02  |  2|Product2|  5
,
-- re-pivot horizontally by date
horiz_pivot_dt AS (
SELECT
  product
, SUM(CASE Service_Date WHEN '2015-06-01' THEN qty END) AS "2015-06-01"
, SUM(CASE Service_Date WHEN '2015-06-02' THEN qty END) AS "2015-06-02"
FROM vert_pivot
GROUP BY
  product
)
SELECT * FROM horiz_pivot_dt
;
-- result:
-- product |2015-06-01|2015-06-02
-- Product1|         1|         2
-- Product2|         3|         5

by the way: I noted that you only pivoted the "column names" and the first column's values - not the measures. My example above did, and I spent a few minutes trying to find out where my error was ....

Happy playing ... marco