Question

我很想读取数据库输出并且字段在数据库中但是它给了我IndexoutofRangeException错误。我声明BLabel就像数据库中的其他值一样。有什么建议吗？

SqlConnection dbConn = null;
StringBuilder sqlString = new StringBuilder();
sqlString.Append("SELECT f.*, v.VersionNumber ");
sqlString.Append("FROM PackLabelFormat f, PackLabelVersion v ");
sqlString.Append(" WHERE f.FormatID = @FormatID ");
sqlString.Append(" AND f.FormatID = v.FormatID ");
sqlString.Append(" AND v.VersionID = (SELECT MAX(VersionID) ");
sqlString.Append("FROM PackLabelVersion v2 ");
sqlString.Append("WHERE v2.FormatID = v.FormatID) ");
try
{
   using (dbConn = new SqlConnection(Properties.Settings.Default["tville"].ToString()))
   {
      SqlCommand cmd = dbConn.CreateCommand();
      cmd.CommandText = sqlString.ToString();
      cmd.Parameters.AddWithValue("@FormatID", FormatID);
      dbConn.Open();

      using (SqlDataReader reader = cmd.ExecuteReader())
      {
         if (reader.HasRows)
         {
            reader.Read();
            FormatName = reader["FormatName"].ToString();
            FormatDescription = reader["FormatDescription"].ToString();
            StockID = Convert.ToInt32(reader["StockID"].ToString());
            PrintCode = bool.Parse(reader["PrintPlantCode"].ToString());
            PrintPrice = bool.Parse(reader["PrintPrice"].ToString());
            PrintWeight = bool.Parse(reader["PrintWeight"].ToString());
            CurrentVersion = reader["VersionNumber"].ToString();
            BLabel = bool.Parse(reader["BSupported"].ToString());
            LLabel = bool.Parse(reader["LSupported"].ToString());
         }
         else
         {
            throw new Exception("No LabelFormat found for ID " + this.FormatID.ToString());
         }
      }
   }
}
catch (Exception ex)
{
   throw ex;
}
finally
{
   if (dbConn != null)
   {
      try { dbConn.Close(); }
      catch { }
   }
}

Answer 1

造成IndexoutofRangeException的原因是我的查询只查找v.VersionNumber而不是我试图检索的所有值，例如BLabel和LLabel。

数据库选择方法给出了IndexoutofRangeException

1 个答案: