SUBSTRING在SQL分区中的使用

Question

I have created a table and partitioned it(the code is here , Please see the Example of horizontal partitioning with creating a new partitioned table part) I have use the following Partition function :

CREATE PARTITION FUNCTION [PartitioningByMonth] (datetime)
AS RANGE RIGHT FOR VALUES ('20140201', '20140301', '20140401',
               '20140501', '20140601', '20140701', '20140801', 
               '20140901', '20141001', '20141101', '20141201'); 

And my SCHEMA is :

CREATE PARTITION SCHEME PartitionBymonth
AS PARTITION PartitioningBymonth
TO (January, February, March, 
    April, May, June, July, 
    Avgust, September, October, 
    November, December);

And My table create Query is :

CREATE TABLE Reports
(ReportDate datetime PRIMARY KEY,
MonthlyReport varchar(max))
ON PartitionBymonth (ReportDate);
GO

if i insert values which are in the year of 2014 (i mean 20140105 , 20140205 , ...... ), it works fine :

INSERT INTO Reports (ReportDate,MonthlyReport)
SELECT '20140105', 'ReportJanuary' UNION ALL
SELECT '20140205', 'ReportFebryary' UNION ALL
SELECT '20140308', 'ReportMarch' UNION ALL

But problem occurs when i insert any value of 2015 , 2016 , 2017 .....:

   INSERT INTO Reports (ReportDate,MonthlyReport)
    SELECT '20150105', 'ReportJanuary' UNION ALL
    SELECT '20150206', 'ReportFebryary' UNION ALL
    SELECT '20150309', 'ReportMarch' UNION ALL

as it push it only the last partition ( 20141201 i mean December partition). But i want them to go January , February , March partition. I know my problem is in PARTITION FUNCTION because i wrote ('20140201', '20140301',......) only for 2014 year. But i want to count the Month only .Is there any way so that it only see the month only 2015 03 01 rather than year or day.(can i use SUBSTRING in any part )

Answer 1

you can add a computed column to your table as

ReportDateP as MONTH(ReportDate) PERSISTED

and create the table with partition on this computed column

Then create the partition function as follows

CREATE PARTITION FUNCTION [NewPartitioning] (int)
AS RANGE RIGHT FOR VALUES (2,3,4,5,6,7,8,9,10,11,12); 

Answer 2

You can not use SubQuery in Partions system. Use Eralper Method for partitioning this portion

CREATE PARTITION SCHEME PartitionBymonth
AS PARTITION PartitioningBymonth
TO (January, February, March, 
    April, May, June, July, 
    Avgust, September, October, 
    November, December);