# Querying Data

## Content



The ADO.NET Provider for Salesforce implements two classes you can use to perform CRUD (Create, Read, Update, and Delete) operations: **DbDataReader** and [C1SalesforceDataAdapter](/componentone/api/services/online-dataconnector/dotnet-standard-api/C1.AdoNet.Salesforce/C1.AdoNet.Salesforce.C1SalesforceDataAdapter.html) classes. The tabs below describe the classes and code implementations.

### Data Reader

### Querying With DbDataReader

The **DbDataReader** class can be used to fetch data in subset increments as required. It can retrieve data quicker than the **C1SalesforceDataAdapter** as it retrieves data in pages. When you read data from the **DbDataReader**, it requests the succeeding page from the data source to load the result, which makes the data retrieval faster.

The following **code examples** demonstrate create, read, update, and delete operations from the data source using the **DbDataReader**.

### Create Data

The example adds new records by executing the **Insert** command.

```csharp
static void InsertDataReader()
{
    Console.WriteLine("Insert operation started !!!");
    using (C1SalesforceConnection conn = new C1SalesforceConnection(GCSalesforceServerConnectionString))
    {
        conn.Open();
        string insertSql = @"Insert into [Order] (AccountId, Status, BillingState,BillingStreet,BillingCity,BillingPostalCode,BillingCountry,EffectiveDate) 
                        Values ('0012w00000Ak4iLAAR', 'Draft','Delhi','Delhi','NCR','110009','India','23-JAN-1992')";
        //Create Insert command;
        C1SalesforceCommand command = new C1SalesforceCommand(conn, insertSql);
        // Execute Insert command
        int i = command.ExecuteNonQuery();
        if (i != -1)
        {
            Console.WriteLine("Insert operation successful !!! \n \n");
        }
    }
}
```

### Read Data

This example retrieves data by executing the **Select** command.

```csharp
static void ReadDataReader()
{
    Console.WriteLine("Read operation started !!!");
    using (C1SalesforceConnection con = new C1SalesforceConnection(GCSalesforceServerConnectionString))
    {
        con.Open();
        //Create Read command
        var cmd = con.CreateCommand();
        cmd.CommandText = "Select  *  FROM [Order] limit 10 ";
        //Execute Read command and display fetched data
        var rdr = cmd.ExecuteReader();
        while (rdr.Read())
        {
            Console.WriteLine(String.Format("\t{0} --> \t\t{1} --> \t\t{2}", rdr["Id"], rdr["AccountId"], rdr["BillingCity"]));
        }
        Console.WriteLine("Read operation successful !!! \n \n");
    }
}
```

### Update Data

This example modifies data by executing the **Update** command.

```csharp
static void UpdateDataReader()
{
    Console.WriteLine("Update operation started !!!");
    using (C1SalesforceConnection conn = new C1SalesforceConnection(GCSalesforceServerConnectionString))
    {
        conn.Open();
        //Create Update command
        C1SalesforceCommand command = new C1SalesforceCommand(conn, "UPDATE [Order] SET BillingCity=@BillingCity where AccountId=@AccountId");
        command.Parameters.AddWithValue("@AccountId", "0012w00000Ak4iLAAR");
        command.Parameters.AddWithValue("@BillingCity", "Delhi");
        //Execute Update command
        int i = command.ExecuteNonQuery();
        if (i != -1)
        {
            Console.WriteLine("Update operation successful !!! \n \n");
        }
    }
}
```

### Delete Data

This example removes data by executing the **Delete** command.

```csharp
static void DeleteDataReader()
{
    Console.WriteLine("Delete operation started!!!");
    using (C1SalesforceConnection conn = new C1SalesforceConnection(GCSalesforceServerConnectionString))
    {
        conn.Open();
        //Create Delete command
        C1SalesforceCommand command = new C1SalesforceCommand(conn, "Delete from [Order] where AccountId = @AccountId ");
        command.Parameters.AddWithValue("@AccountId", "0012w00000Ak4iLAAR");
        //Execute Delete command
        int i = command.ExecuteNonQuery();
        if (i != -1)
        {
            Console.WriteLine("Delete operation successful !!! \n \n");
        }
    }
}
```

### Data Adapter

### Querying With C1SalesforceDataAdapter

The **C1SalesforceDataAdapter** class can be used to retrieve a single result set containing all the data that matches a given query. The C1SalesforceDataAdapter uses its Fill method to fetch data from the data source. An empty DataTable instance is passed as an argument to the Fill method. Once the method returns, the DataTable instance is populated with the queried data. Since the Fill method must retrieve all the data from the data source before returning, the **C1SalesforceDataAdapter** is slower compared to the **DbDataReader**.

The following **code examples** demonstrate create, read, update, and delete operations from the data source using the **C1SalesforceDataAdapter**.

### Create Data

The example adds new records by executing the **Insert** command.

```csharp
static void InsertDataAdapter()
{
    using (C1SalesforceConnection conn = new C1SalesforceConnection(GCSalesforceServerConnectionString))
    {
        //Populate DataTable
        C1SalesforceDataAdapter adapter = new C1SalesforceDataAdapter(conn, "Select * from [Order]");
        DataTable dataTable = new DataTable();
        adapter.Fill(dataTable);
        //Create Insert command
        adapter.InsertCommand = new C1SalesforceCommand(conn);
        adapter.InsertCommand.CommandText = "Insert into [Order] (AccountId,Status,BillingState,BillingCountry,EffectiveDate) values (@AccountId,@Status,@BillingState,@BillingCountry,@EffectiveDate)";
        adapter.InsertCommand.Parameters.Add("@AccountId", "AccountId");
        adapter.InsertCommand.Parameters.Add("@Status", "Status");
        adapter.InsertCommand.Parameters.Add("@BillingState", "BillingState");
        adapter.InsertCommand.Parameters.Add("@BillingCountry", "BillingCountry");
        adapter.InsertCommand.Parameters.Add("@EffectiveDate", "EffectiveDate");
        adapter.InsertCommand.UpdatedRowSource = UpdateRowSource.None;
        //Insert new row
        DataRow orderRow1 = dataTable.NewRow();
        orderRow1["AccountId"] = "0012w00000Ak4iLAAR";
        orderRow1["Status"] = "Draft";
        orderRow1["BillingState"] = "Delhi";
        orderRow1["BillingCountry"] = "India";
        orderRow1["EffectiveDate"] = "23-Jan-1992";
        dataTable.Rows.Add(orderRow1);
        //Update database
        adapter.Update(dataTable);
    }
}
```

### Read Data

This example retrieves data by executing the **Select** command.

```csharp
static void ReadDataAdapter()
{
    using (C1SalesforceConnection con = new C1SalesforceConnection(GCSalesforceServerConnectionString))
    {
        //Populate DataTable
        C1SalesforceConnection conn = new C1SalesforceConnection(GCSalesforceServerConnectionString);
        C1SalesforceDataAdapter adapter = new C1SalesforceDataAdapter(conn, "Select * from [Order] limit 10");
        DataTable dataTable = new DataTable();
        adapter.Fill(dataTable);
        //Display fetched data
        foreach (DataRow row in dataTable.Rows)
        {
            Console.WriteLine("{0}\t{1}", row["AccountId"], row["BillingState"]);
        }
    }
```

### Update Data

This example modifies data by executing the **Update** command.

```csharp
static void UpdateDataAdapter()
{
    using (C1SalesforceConnection conn = new C1SalesforceConnection(GCSalesforceServerConnectionString))
    {
        //Populate DataTable
        C1SalesforceDataAdapter adapter = new C1SalesforceDataAdapter(conn, "Select * from [Order]");
        DataTable dataTable = new DataTable();
        adapter.Fill(dataTable);
        //Create Update command
        adapter.UpdateCommand = new C1SalesforceCommand(conn);
        adapter.UpdateCommand.CommandText = "UPDATE [Order] SET BillingState=@BillingState where AccountId=@AccountId";
        adapter.UpdateCommand.Parameters.Add("@BillingState", "BillingState");
        adapter.UpdateCommand.Parameters.Add("@AccountId", "AccountId");
        adapter.UpdateCommand.UpdatedRowSource = UpdateRowSource.None;
        //Update existing row
        DataRow OrderRow1 = dataTable.Rows[0];
        OrderRow1["AccountId"] = "0012w00000Ak4iLAAR";
        OrderRow1["BillingState"] = "Mumbai";
        //Update database
        adapter.Update(dataTable);
    }
}
```

### Delete Data

This example removes data by executing the **Delete** command.

```csharp
static void DeleteDataAdapter()
{
    using (C1SalesforceConnection conn = new C1SalesforceConnection(GCSalesforceServerConnectionString))
    {
        //Populate Datatable
        C1SalesforceDataAdapter adapter = new C1SalesforceDataAdapter(conn, "Select * from [Order]");
        DataTable dataTable = new DataTable();
        adapter.Fill(dataTable);
        //Create Delete command
        adapter.DeleteCommand = new C1SalesforceCommand(conn);
        adapter.DeleteCommand.CommandText = "Delete from [Order] where AccountId=@AccountId";
        adapter.DeleteCommand.Parameters.Add("@AccountId", "AccountId");
        adapter.DeleteCommand.UpdatedRowSource = UpdateRowSource.None;
        //Delete a row
        DataRow OrderRow1 = dataTable.Rows[3];
        OrderRow1["AccountId"] = "8012w000000djLDAAY";
        OrderRow1.Delete();
        //Update Database
        adapter.Update(dataTable);
    }
}
```