Question

I want to transfer a large amount of data from F# to an SQL table. Basically my F# code creates a matrix of three columns (UserID, ProductID and price) and N lines. I would like to “copy/pate it” into a database
I tried several options but at the end, the transfer of data from F# is really slow (around one hour for 10000 lines).

Thanks to answers of a previous question How to include a stored procedure in F#, an interesting way to resolve this problem is to use SqlBulkCopy.

SqlBulkCopy requires a database type for its WritetoServer method but I didn’t find any existing code or simple way to convert a matrix into a database.
Do you have any suggestions or ideas?

Answer 1

This should get you started (and reference the documentation for more information about SqlBulkCopy):

//you must reference System.Data and System.Xml
open System.Data
open System.Data.SqlClient

let bulkLoadUserPurchases (conn:SqlConnection) (userPurchases: list<int * int * float>) =
    use sbc = new SqlBulkCopy(conn, SqlBulkCopyOptions.TableLock, null, BatchSize=500, BulkCopyTimeout=1200, DestinationTableName="YOUR_TABLE_NAME_HERE")
    sbc.WriteToServer(
        let dt = new DataTable()
        ["UserID", typeof<int>
         "ProductID", typeof<int>
         "Price", typeof<float>]
        |> List.iter (dt.Columns.Add>>ignore)

        for userPurchase in userPurchases do
            let userId, productId, price = userPurchase
            let dr = dt.NewRow()
            dr.["UserID"] <- userId
            dr.["ProductID"] <- productId
            dr.["Price"] <- price
            dt.Rows.Add(dr)

        dt)