DB2DataReader.NextResultAsync Method

An asynchronous version of NextResult, which advances the reader to the next result when reading the results of a batch of statements. Invokes NextResultAsync with CancellationToken.None. (Inherited from DbDataReader.)

Namespace:: IBM.Data.DB2
Assembly:: IBM.Data.DB2 (in IBM.Data.DB2.dll)

Syntax


[Visual Basic]
Public  Function NextResultAsync  As Task(Of  Boolean)
[C#]
public Task< bool> NextResultAsync()
[C++]
Task<bool>^ NextResultAsync()
[JScript] 
public   function  NextResultAsync() : Task< boolean >

Return value

A task representing the asynchronous operation.

Remarks

The first level support of DB2DataReader.NextResultAsync uses a mix of asynchronous and synchronous code due to dependencies on unmanaged components such as CSM, HADR and DRDA.

Example

// Customer
private  struct  Customer
{
public  long     CustomerID;
public  string  FirstName;
public  string  LastName;
}

// Gets the specific customer by reading the next result set asynchronously

private  async  Task  <Customer> GetCustomerAsync(  string  myConnString)
{
// This simple select query fetches thousands of rows from an existing CUSTOMERS table,
// and may require handling of network packets asynchronously by calling DB2DataReader.ReadAsync()
string  mySelectQuery =  "SELECT * FROM CUSTOMERS; SELECT TOP 1 * FROM CUSTOMERS ORDER BY LastName"  ;

using  (DB2Connection myConnection =  new  DB2Connection(myConnString))
{
    myConnection.Open();

    Customer customer =  new  Customer();

    using  (DB2Command myCommand =  new  DB2Command(mySelectQuery, myConnection))
    {
        using  (DB2DataReader myReader = myCommand.ExecuteReader())
        {  
          if (awaitmyReader.ReadAsync())
            {
              // Do some operations...
            }
          //This will allow leftover rows in the first result set to be read off asynchronously
      
            if  (  await  myReader.NextResultAsync())
            {
                if  (  await  myReader.ReadAsync())
                {
                    // Get the second Result Set's Customer i.e. the first Customer sorted by LastName
                    customer.CustomerID = myReader.GetInt64(0);
                    customer.FirstName = myReader.GetString(1);
                    customer.LasttName = myReader.GetString(2);
                }
            }
        }
    }

    return customer;
}