LinkarClientUpdate Method

Linkar Framework for .NET and Core

Update one or several records of a file, synchronously only, with JSON input and output format.

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

Syntax

C++

Copy

public string Update(
	string filename,
	string records,
	UpdateOptions updateOptions = null,
	JSON_FORMAT jsonFormat = JSON_FORMAT.JSON,
	string customVars = "",
	int receiveTimeout = 0
)

Public Function Update ( 
	filename As String,
	records As String,
	Optional updateOptions As UpdateOptions = Nothing,
	Optional jsonFormat As JSON_FORMAT = JSON_FORMAT.JSON,
	Optional customVars As String = "",
	Optional receiveTimeout As Integer = 0
) As String

public:
String^ Update(
	String^ filename, 
	String^ records, 
	UpdateOptions^ updateOptions = nullptr, 
	JSON_FORMAT jsonFormat = JSON_FORMAT::JSON, 
	String^ customVars = L"", 
	int receiveTimeout = 0
)

member Update : 
        filename : string * 
        records : string * 
        ?updateOptions : UpdateOptions * 
        ?jsonFormat : JSON_FORMAT * 
        ?customVars : string * 
        ?receiveTimeout : int 
(* Defaults:
        let _updateOptions = defaultArg updateOptions null
        let _jsonFormat = defaultArg jsonFormat JSON_FORMAT.JSON
        let _customVars = defaultArg customVars ""
        let _receiveTimeout = defaultArg receiveTimeout 0
*)
-> string

Parameters

filename String: Name of the file being updated.
records String: Buffer of record data to update. Inside this string are the recordIds, the modified records, and the originalRecords.
updateOptions UpdateOptions (Optional): Object with write options, including optimisticLockControl, readAfter, calculated, dictionaries, conversion, formatSpec, originalRecords.
jsonFormat JSON_FORMAT (Optional): Enum JSON_FORMAT specifies the desired output format: standard JSON, JSON_DICT format, or JSON_SCH format
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

String
The results of the operation.

Remarks

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

Example

C++

Copy

using Linkar;
using Linkar.Functions.Persistent.JSON;

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

                result = client.Update("LK.CUSTOMERS", 
                    "{" +
                    "  \"RECORDS\": [" +
                    "    {" +
                    "      \"LKITEMID\": \"2\"," +
                    "      \"NAME": \"CUSTOMER 2\"," +
                    "      \"ADDR": \"ADDRESS 2\"," +
                    "      \"PHONE": \"444\"" +
                    "    }" +
                    "  ]" +
                    "}");
                client.Logout();
            }
            catch (Exception ex)
            {
                string error = ex.Message;
                // Do something
            }
            return result;
        }
    }

Imports Linkar
Imports Linkar.Functions.Persistent.JSON

Class Test

    Public Function MyUpdate() 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.Update("LK.CUSTOMERS",
                "{" +
                "  \"RECORDS\": [" +
                "    {" +
                "      \"LKITEMID\": \"2\"," +
                "      \"NAME": \"CUSTOMER 2\"," +
                "      \"ADDR": \"ADDRESS 2\"," +
                "      \"PHONE": \"444\"" +
                "    }" +
                "  ]" +
                "}")

            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.JSON Namespace