LinkarClientDeleteAsync Method

Linkar Framework for .NET and Core

Deletes one or several records in file, in a asynchronous way with MV input and output format.

Namespace: Linkar.Functions.Persistent.MV
Assembly: Linkar.Functions.Persistent.MV (in Linkar.Functions.Persistent.MV.dll) Version: 2.3.1

Syntax

C++

Copy

public Task<string> DeleteAsync(
	string filename,
	string records,
	DeleteOptions deleteOptions = null,
	string customVars = "",
	int receiveTimeout = 0
)

Public Function DeleteAsync ( 
	filename As String,
	records As String,
	Optional deleteOptions As DeleteOptions = Nothing,
	Optional customVars As String = "",
	Optional receiveTimeout As Integer = 0
) As Task(Of String)

public:
Task<String^>^ DeleteAsync(
	String^ filename, 
	String^ records, 
	DeleteOptions^ deleteOptions = nullptr, 
	String^ customVars = L"", 
	int receiveTimeout = 0
)

member DeleteAsync : 
        filename : string * 
        records : string * 
        ?deleteOptions : DeleteOptions * 
        ?customVars : string * 
        ?receiveTimeout : int 
(* Defaults:
        let _deleteOptions = defaultArg deleteOptions null
        let _customVars = defaultArg customVars ""
        let _receiveTimeout = defaultArg receiveTimeout 0
*)
-> Task<string>

Parameters

filename String: The file name where the records are going to be deleted. DICT in case of deleting a record that belongs to a dictionary.
records String: Buffer of records to be deleted. Use StringFunctions.ComposeDeleteBuffer (Linkar.Strings library) function to compose this string.
deleteOptions DeleteOptions (Optional): Object with options to manage how records are deleted, including optimisticLockControl, recoverRecordIdType.
customVars String (Optional): Free text sent to the database allows management of additional behaviours in SUB.LK.MAIN.CONTROL.CUSTOM, which is called when this parameter is set.
receiveTimeout Int32 (Optional): Maximum time in seconds that the client will wait for a response from the server. Default = 0 to wait indefinitely.

Return Value

TaskString
The results of the operation.

Remarks

Inside the records argument, the recordIds always must be specified. But the originalRecords not always. When deleteOptions argument is specified and the OptimisticLockControl property is set to true, a copy of the record must be provided before the deletion (originalRecords argument) to use the Optimistic Lock technique. This copy can be obtained from a previous ReadAsync(String, String, String, ReadOptions, String, Int32) operation. The database, before executing the deletion, reads the record and compares it with the copy in originalRecords, if they are equal the record is deleted. But if they are not equal, it means that the record has been modified by other user and the record will not be deleted. The record will have to be read, and deleted again.

Example

C++

Copy

using Linkar;
using Linkar.Functions.Persistent.MV;

class Test
    {
        public string MyDelete()
        {
            string result = "";
            try
            {
                CredentialOptions credentials = new CredentialOptions("127.0.0.1", "EPNAME", 11300, "admin", "admin");
                LinkarClient client = new LinkarClient();
                client.Login(credentials);

                result = client.DeleteAsync("LK.CUSTOMERS", "2" + ASCII_Chars.FS_chr + "").Result;
                client.Logout();
            }
            catch (Exception ex)
            {
                string error = ex.Message;
                // Do something
            }
            return result;
        }
    }

Imports Linkar
Imports Linkar.Functions.Persistent.MV

Class Test

    Public Function MyDelete() As String
        Dim result As String = ""

        Try
            Dim credentials As CredentialOptions = New CredentialOptions("127.0.0.1", "EPNAME", 11300, "admin", "admin")

            Dim client As LinkarClient = New LinkarClient()

            client.Login(credentials)

            result = client.DeleteAsync("LK.CUSTOMERS", "2" + ASCII_Chars.FS_chr + "").Result

            client.Logout()
        Catch ex As Exception
            Dim[error] As String = ex.Message
            ' Do something

        End Try

        Return result
  End Function
End Class

Reference

LinkarClient Class

Linkar.Functions.Persistent.MV Namespace