Convert sql to linq with STRING_AGG - sql

Question

convert sql to linq that has STRING_AGG
SELECT
V.pkid,
V.[Name] AS VendorName,
SFTP.SFTP_Paths AS SFTP_Paths
FROM
dbo.Vendor V
LEFT OUTER JOIN (
SELECT
connected_to,
STRING_AGG(rootfolder, ', ') AS SFTP_Paths
FROM
dbo.FTP
WHERE
connected_to_type = 4 -- Vendor
GROUP BY
connected_to
) SFTP ON v.pkid = SFTP.connected_to
WHERE
V.active = 1
order by
V.[name]

Answer 1

This query returns the same sql query result.
Instead of STRING_AGG (rootfolder, ',') AS SFTP_Paths I used SFTP_Paths = string.Join(",", b.Select (c => c.rootfolder).ToArray()) for equivalence.
The rest of the query is understandable.
var query = vendorList.Join(lstFtp.Where(x => x.connected_to_type == 4).GroupBy(a => a.connected_to)
.Select(b => new
{
connected_to = b.Key,
SFTP_Paths = b.Select(c => c.rootfolder).ToList()
}).AsEnumerable()
.Select(b => new
{
connected_to = b.connected_to,
SFTP_Paths = string.Join(",", b.SFTP_Paths).ToArray()
}),
right => right.pkid,
left => left.connected_to,
(right, left) => new
{
V = right,
SFTP = left
}).Where(d => d.V.active == 1)
.Select(e => new
{
pkid = e.V.pkid,
VendorName = e.V.Name,
SFTP_Paths = e.SFTP.SFTP_Paths
})
.OrderBy(e => e.VendorName).ToList();