bulk insert into particular colums

Good points from @tesuji about format files — they let a server-side bulk operation map or skip fields. The key reason your view trick failed is that BULK INSERT runs on the SQL Server host and expects the data file to be reachable from that host (local path or a UNC share that the SQL Server service can access). For a remote client that owns the file, don’t rely on server-side BULK INSERT unless you can place the file where the server can read it. (learn.microsoft.com)

For a C# client the simplest, fastest fix is SqlBulkCopy: it streams from your process (no server-side file required) and supports explicit column mappings so you can load only user_name and u_id and let the table defaults (GUID, GETDATE, etc.) populate the rest. Use ColumnMappings and set sensible BatchSize/BulkCopyTimeout to avoid long-running single transactions. If you need triggers or constraint checking during the load, enable the corresponding SqlBulkCopyOptions flags (FireTriggers, CheckConstraints). Example pattern:

// build a small DataTable with the two columns, or implement an IDataReader
using(var conn = new SqlConnection(connString))
using(var bulk = new SqlBulkCopy(conn))
{
    bulk.DestinationTableName = "dbo.YourTable";
    bulk.ColumnMappings.Add("user_name","user_name");
    bulk.ColumnMappings.Add("u_id","u_id");
    bulk.BatchSize = 5000;
    conn.Open();
    bulk.WriteToServer(dataTable);
}

SqlBulkCopy docs and option flags explain the properties and flags. (learn.microsoft.com)

If you prefer a command-line route, run the bcp utility from the client machine (it sends the file to SQL Server over the network and can use a format file to map/skip fields). Example:

bcp "MyDb.dbo.YourTable" in "C:\temp\users.txt" -S MyServer -T -c -t " " -f "C:\temp\users.fmt"

Use bcp when you want a quick file->table tool; use BULK INSERT only when the file can be placed on a path the server can read. Note: BULK INSERT always enforces UNIQUE/PK constraints and will error on duplicates; CHECK/FK behavior differs unless you request constraint checking. (learn.microsoft.com)

Practical checklist: stream the input (avoid building huge strings), use SqlBulkCopy with column mappings and a moderate BatchSize, load into a staging table and MERGE into production if you need de-duplication or validation, and re‑validate constraints after a bulk load. For ~60K rows SqlBulkCopy with BatchSize set should complete quickly and not hang.