Dynamic data perspective query using PostgreSQL 9.3

create table product (
 ProductNumber varchar(10) ,
 ProductName varchar(10),
 SalesQuantity int,
 Salescountry varchar(10)
);

insert into product values
 ('P1','PenDrive', 50,'US')
, ('P2','Mouse', 100,'UK') 
, ('P3','KeyBoard', 250,'US')
, ('P1','PenDrive', 300,'US')
, ('P2', 'Mouse', 450,'UK')
, ('P5','Dvd', 50,'UAE');

ProductName US UK UAE
------------- ---------------
PenDrive 350 0 0
Mouse 0 550 0
KeyBoard 250 0 0
Dvd 0 0 50

DECLARE @cols AS NVARCHAR(MAX),
 @query AS NVARCHAR(MAX);

SET @cols = STUFF((SELECT distinct',' + QUOTENAME(SalesCountry) 
 FROM Product
 FOR XML PATH(''), TYPE
 ).value('.','NVARCHAR(MAX)') 
 ,1,1,'')

set @query ='SELECT ProductName, '+ @cols +' from 
 (
 select ProductName
, SalesQuantity as q
, Salescountry
 from Product
) x
 pivot 
 (
 SUM(q)
 for Salescountry in ('+ @cols +')
) p'

PRINT(@query);
execute(@query);

SELECT *
FROM crosstab (
'SELECT ProductNumber, ProductName, Salescountry, SalesQuantity
 FROM product
 ORDER BY 1'
, $$SELECT unnest('{US,UK,UAE1}'::varchar[])$$
 ) AS ct (
 "ProductNumber" varchar
, "ProductName" varchar
, "US" int
, "UK" int
, "UAE1" int); 

I have a table called Product:

create table product (
 ProductNumber varchar(10),
 ProductName varchar(10),
 SalesQuantity int,
 Salescountry varchar(10)
);

Sample value:

insert into product values
 ('P1','PenDrive', 50,'US' )
, ('P2','Mouse', 100,'UK')
, ('P3','KeyBoard', 250,'US')
, ('P1' ,'PenDrive', 300,'US')
, ('P2','Mouse', 450,'UK')
, ('P5','Dvd', 50,'UAE' );

I want to dynamically generate the name of Salescountry and display the total sales volume of SalesQuantity in that country.

Expected results:

 ProductName US UK UAE
----------------------------
PenDrive 350 0 0
Mouse 0 550 0
KeyBoard 250 0 0
Dvd 0 0 50

I did it with SQL Server 2008 R2:

DECLARE @ cols AS NVARCHAR(MAX),
 @query AS NVARCHAR(MAX);

SET @cols = STUFF((SELECT dis tinct',' + QUOTENAME(SalesCountry) 
 FROM Product
 FOR XML PATH(''), TYPE
 ).value('.','NVARCHAR(MAX)') 
 ,1,1,'')

set @query ='SELECT ProductName, '+ @cols +' from 
 (
 select ProductName
, SalesQuantity as q
, Salescountry
 from Product
) x
 pivot 
 (
 SUM(q)
 for Salescountry in ('+ @cols + ')
) p'

PRINT(@query);
execute(@query);

How to achieve this goal in Postgres?

SELECT *
FROM crosstab (
'SELECT ProductNumber, ProductName, Salescountry, SalesQuantity
 FROM product< br /> ORDER BY 1'
, $$SELECT unnest('{US,UK,UAE1}'::varchar[])$$
) AS ct (
 "ProductNumber" varchar 
, "ProductName" varchar
, "US" int
, "UK" int
, "UAE1" int);

Detailed description:

> PostgreSQL Crosstab Query
> Pivot on Multiple Columns using Tablefunc

Perform full dynamic query on different number of different Salescountry?

> Dynamic alternative to pivot with CASE and GROUP BY