Reporting services 如何为SSRS中的自定义代码添加System.Data.SqlClient引用？

您需要从报表属性U/I添加对程序集的引用

请查看此处的步骤和注意事项：

public string getLabel(int ReportID, int labelID)
{
    string s;
    System.Data.SqlClient.SqlConnection myConnection = new System.Data.SqlClient.SqlConnection("Data Source=*****;Persist Security Info=True;Password=****;User ID=*********;Initial Catalog=iLoyaltyDW");
    SqlCommand myCommand = new SqlCommand();
    myCommand.Connection = myConnection;
    myCommand.CommandType = CommandType.Text;
    myCommand.CommandText = "select ....";
    myConnection.Open();

    SqlDataReader reader = myCommand.ExecuteReader();

    while (reader.Read())
    {
        s = reader.GetString(0);
    }

    return s;         
}