dotConnect for Zoho CRM Documentation
Retrieving Data

Introduction

This tutorial describes how to use ZohoCommand, ZohoDataReader, and ZohoDataAdapter components.

Requirements

This tutorial supposes that you know how to connect to server.

Note that if you do not use design-time (specifically, if you do not place on a designer ZohoConnection component from toolbox), you have to embed license information manually. This is described in the Licensing topic.

General Information

The main function of any database application is establishing a connection to a data source and working with data contained in it. ADO.NET data providers serve as a bridge between an application and a data source, and allow you to execute commands as well as to retrieve data by using a DataReader or a DataAdapter. Updating data involves using the Command and DataAdapter objects.

Retrieving Data using ZohoCommand and ZohoDataReader

In this sample we will use ZohoCommand and ZohoDataReader to retrieve data. ZohoDataReader allows retrieving data in pages. While you read data from it, it automatically queries next pages from Zoho CRM. ZohoDataReader offers higher performance than ZohoDataAdapter, especially when you query a lot of data. For more information, refer to the description of these classes in our documentation.

using Devart.Data.Zoho;
...
class Program
{
    static void Main(string[] args) {

        const string connectionString = "security token=d3c6452922f65c24b59c75aee0d0112b;";
        const string sql = "SELECT \"Account Name\", WebSite FROM Accounts";

        using (ZohoConnection connection = new ZohoConnection(connectionString)) {

            connection.Open();
            using (ZohoCommand command = connection.CreateCommand()) {

                command.CommandText = sql;
                using (ZohoDataReader reader = command.ExecuteReader()) {

                    while (reader.Read()) {

                        Console.WriteLine("{0}\t{1}", reader.GetValue(0), reader.GetValue(1));
                    }
                }
            }
        }
        Console.ReadKey();
    }

}
Imports Devart.Data.Zoho
...
Module Module1

    Sub Main()

        Const connectionString As String = "security token=d3c6662922f65c14b59d75dee0d0442b;"
        Const sql As String = "SELECT ""Account Name"", WebSite FROM Accounts"

        Using connection As New ZohoConnection(connectionString)

            connection.Open()
            Using command As ZohoCommand = connection.CreateCommand()

                command.CommandText = sql
                Using reader As ZohoDataReader = command.ExecuteReader()

                    While reader.Read()

                        Console.WriteLine(reader.GetValue(0) & vbTab & reader.GetValue(1))
                    End While
                End Using
            End Using
        End Using
        Console.ReadKey()
    End Sub

End Module


Retrieving Data using ZohoDataAdapter

Applicable only for projects targeting full .NET Framework.

In this sample we will use the ZohoDataAdapter component. It retrieves data when you call its Fill method. Note that this method needs to retrieve all the queried data from Zoho CRM, and it can take some time.

Here is a small sample that demonstrates usage of ZohoDataAdapter to retrieve data.

    static void Main(string[] args) {

        const string connectionString = "security token=d3c6662922f65c14b59d75dee0d0442b;";
        const string sql = "SELECT \"Account Name\", WebSite FROM Accounts";

        using (ZohoConnection connection = new ZohoConnection(connectionString)) {

            connection.Open();
            var table = new System.Data.DataTable("Campaigns");

            using (ZohoCommand command = connection.CreateCommand()) {

                command.CommandText = sql;
                using (ZohoDataAdapter adapter = new ZohoDataAdapter(command)) {
                    adapter.Fill(table);
                }
            }

            foreach (DataRow row in table.Rows) {
                Console.WriteLine("{0}\t{1}", row[0], row[1]);
            }
        }
        Console.ReadKey();
    }


    Sub Main()

        Const connectionString As String = "security token=d3c6452922f65c24b59c75aee0d0112b;"
        Const sql As String = "SELECT ""Account Name"", WebSite FROM Accounts"

        Using connection As New ZohoConnection(connectionString)

            connection.Open()
            Dim table As New System.Data.DataTable("Campaigns")

            Using command As ZohoCommand = connection.CreateCommand()

                command.CommandText = sql
                Using adapter As New ZohoDataAdapter(command)
                    adapter.Fill(table)
                End Using
            End Using

            For Each row As DataRow In table.Rows
                Console.WriteLine(row(0) & vbTab & row(1))
            Next
        End Using
        Console.ReadKey()
    End Sub


Custom Object Support

dotConnect for Zoho CRM fully supports Zoho CRM custom objects and fields and can retrieve their data in the same way as with predefined objects.

Additional Information

This tutorial describes only basic ways of working with data. For example, you can take advantage of using Entity Framework ORM technology which is intended for converting data between incompatible type systems in different data sources and object-oriented programming languages. This technology allow you to decrease the amount of code and maintenance required for data-oriented applications. For more information, please refer to Entity Framework section.

See Also

Entity Framework  | Updating Data