Previously, I requested how to create a directory within a FileTable
without using File I/O APIs. I now want to create a subdirectory to the parent directory I just created. How do assign my parent during insert? It appears that parent_path_locator
is a computed column.
This creates my parent...
INSERT INTO FileTable0 (name,is_directory,is_archive) VALUES ('Directory', 1, 0);
How do I create a child directory to this parent in my FileTable?
This is what I ended up using to create a subdirectory since GetPathLocator()
won't generate a new path_locator
value for me - it will only interpret existing hierarchyids
.
DECLARE @parentdir table(path hierarchyid not null);
DECLARE @subdir_locator hierarchyid
-- Create Parent Directory, OUTPUT inserted parent path
INSERT INTO FileTable0 (name,is_directory,is_archive)
OUTPUT INSERTED.path_locator into @parentdir
SELECT 'Directory', 1, 0
-- Create new path_locator based upon parent
SELECT @subdir_locator = dbo.GetNewPathLocator(path) from @parentdir
-- Create Subdirectory
INSERT INTO FileTable0 (name,path_locator,is_directory,is_archive)
VALUES ('subdirectory', @subdir_locator, 1, 0);
The above code block utilizes the default path_locator value discovered here that builds a new hierarchyid
representation from a GUID (utilizing newid()
method, and simple parsing). The function GetNewPathLocator()
does not exist anywhere in SQL Server that I could find (hierarchyid.GetDescendant()
is the closest I could find, but it didn't use the native structure that FileTable relies on). Maybe in SQL.NEXT...
CREATE FUNCTION dbo.GetNewPathLocator (@parent hierarchyid = null) RETURNS varchar(max) AS
BEGIN
DECLARE @result varchar(max), @newid uniqueidentifier -- declare new path locator, newid placeholder
SELECT @newid = new_id FROM dbo.getNewID; -- retrieve new GUID
SELECT @result = ISNULL(@parent.ToString(), '/') + -- append parent if present, otherwise assume root
convert(varchar(20), convert(bigint, substring(convert(binary(16), @newid), 1, 6))) + '.' +
convert(varchar(20), convert(bigint, substring(convert(binary(16), @newid), 7, 6))) + '.' +
convert(varchar(20), convert(bigint, substring(convert(binary(16), @newid), 13, 4))) + '/'
RETURN @result -- return new path locator
END
GO
The function GetNewPathLocator()
also requires a SQL view getNewID
for requesting a newid()
using the trick from this SO post.
create view dbo.getNewID as select newid() as new_id
To call GetNewPathLocator()
, you can use the default parameter which will generate a new hierarchyid
or pass in an existing hiearchyid
string representation (.ToString()
) to create a child hierarchyid
as seen below...
SELECT dbo.GetNewPathLocator(DEFAULT); -- returns /260114589149012.132219338860058.565765146/
SELECT dbo.GetNewPathLocator('/260114589149012.132219338860058.565765146/'); -- returns /260114589149012.132219338860058.565765146/141008901849245.92649220230059.752793580/