To modify existing records, use UPDATE statements.

Update Syntax

The UPDATE statement takes as input a comma-separated list of columns and new column values as name-value pairs in the SET clause, as shown in the following example:

UPDATE <table_name> SET <select_statement> | {<column_reference> = <expression> [ , ... ]} WHERE { ItemId = <expression>  } [ { AND | OR } ... ] 

<expression> ::=
  | @ <parameter> 
  | ?
  | <literal>

You can use the ExecuteNonQuery method to execute data manipulation commands and retrieve the rows affected, as shown in the following example:

C#

String connectionString = "DevID=MyDevID;OAuthClientId=MyAppID;OAuthClientSecret=MyCertID;RuName=MyRuName;SiteID=0;OAuthAccessToken=MyOAuthAccessToken";
using (EbayConnection connection = new EbayConnection(connectionString)) {
  int rowsAffected;
  EbayCommand cmd = new EbayCommand("UPDATE ItemListing SET Title='My Awesome Book II' WHERE ItemId = @myItemId", connection);
  cmd.Parameters.Add(new EbayParameter("myItemId","Jq74mCczmFXk1tC10GB"));
  rowsAffected = cmd.ExecuteNonQuery();
}

VB.NET

Dim connectionString As [String] = "DevID=MyDevID;OAuthClientId=MyAppID;OAuthClientSecret=MyCertID;RuName=MyRuName;SiteID=0;OAuthAccessToken=MyOAuthAccessToken"
Using connection As New EbayConnection(connectionString)
  Dim rowsAffected As Integer
  Dim cmd As New EbayCommand("UPDATE ItemListing SET Title='My Awesome Book II' WHERE ItemId = @myItemId", connection)
  cmd.Parameters.Add(New EbayParameter("myItemId", "Jq74mCczmFXk1tC10GB"))
  rowsAffected = cmd.ExecuteNonQuery()
End Using