String not in correct format

Question

Hello Team In my MVC controller I keep having this error in this code Convert.ToInt32(OrderNumber) which says that the Input string is not in correct format and I realised it in my Sql Database table i used the data type as Varchar so I tried to re-write the code as Convert.ToString(OrderNumber).ToList() but this one to didn't work kindly assist please. if (!string.IsNullOrEmpty(OrderNumber) && OrderNumber != null) { modifiedData = modifiedData.Where(a => a.OrderId == Convert.ToInt32(OrderNumber)).OrderBy(x => x.OrderDate).ThenBy(x => x.Qty).ToList(); } if (!string.IsNullOrEmpty(sDate) && !string.IsNullOrEmpty(eDate)) { DateTime fromDate = DateTime.Parse(sDate); DateTime toDate = DateTime.Parse(eDate); modifiedData = modifiedData.Where(a => DateTime.Parse(a.OrderDate) >= fromDate && DateTime.Parse(a.OrderDate) x.OrderDate).ThenBy(x => x.Qty).ToList(); }

Jayraj Chhaya · Answer

Hello The error you are experiencing arises because the OrderNumber is stored as a varchar in your SQL database which may contain non-numeric characters or be empty. To resolve this you should first ensure that the OrderNumber can be safely converted to an integer. Instead of using Convert.ToInt32  consider using int.TryParse  which allows you to handle conversion failures gracefully. Here’s a revised version of your code: if (!string.IsNullOrEmpty(OrderNumber) && OrderNumber != null) { int orderId; if (int.TryParse(OrderNumber out orderId)) { modifiedData = modifiedData .Where(a => a.OrderId == orderId) .OrderBy(x => x.OrderDate) .ThenBy(x => x.Qty) .ToList(); } else { // Handle the case where OrderNumber is not a valid integer // For example log the error or return a message to the user } } if (!string.IsNullOrEmpty(sDate) && !string.IsNullOrEmpty(eDate)) { DateTime fromDate = DateTime.Parse(sDate); DateTime toDate = DateTime.Parse(eDate); modifiedData = modifiedData .Where(a => DateTime.Parse(a.OrderDate) >= fromDate && DateTime.Parse(a.OrderDate) x.OrderDate) .ThenBy(x => x.Qty) .ToList(); }

Emmmanuel FIADUFE · Answer

Hello Team Thank you for your swift response but however the this the error that came after implementing both format you posted here please.

Naveen Kumar · Answer

Hi Emmmanuel Please check the below code. if (!string.IsNullOrEmpty(OrderNumber) && OrderNumber != null) { // Attempt to parse OrderNumber as an integer if (int.TryParse(OrderNumber out int orderNumberInt)) { modifiedData = modifiedData .Where(a => a.OrderId == orderNumberInt) .OrderBy(x => x.OrderDate) .ThenBy(x => x.Qty) .ToList(); } else { // Handle the case where OrderNumber is not a valid integer // You might log this as an error throw an exception or ignore this filter // For example: throw new FormatException(OrderNumber is not in a valid integer format.); } } if (!string.IsNullOrEmpty(sDate) && !string.IsNullOrEmpty(eDate)) { // Parse the dates DateTime fromDate = DateTime.Parse(sDate); DateTime toDate = DateTime.Parse(eDate); modifiedData = modifiedData .Where(a => DateTime.Parse(a.OrderDate) >= fromDate && DateTime.Parse(a.OrderDate) x.OrderDate) .ThenBy(x => x.Qty) .ToList(); }

Jayraj Chhaya · Answer

Hi Emmmanuel FIADUFE Could you share a screenshot or details of the `OrderNumber` variable values you received? It looks like there might be an invalid value like a character or another non-numeric entry which could be causing an error when parsing to an integer. Please share the details as a screenshot or a code snippet.

Emmmanuel FIADUFE · Answer

Hello Jayraj Please this is the error I encounter again.

Jayraj Chhaya · Answer

Hi Emmmanuel FIADUFE Try the updated code We can enhance the validation of the OrderNumber before attempting to parse it. if (!string.IsNullOrEmpty(OrderNumber) && OrderNumber.Trim() != null) { // Attempt to parse OrderNumber as an integer if (int.TryParse(OrderNumber out int orderNumberInt)) { modifiedData = modifiedData .Where(a => a.OrderId == orderNumberInt) .OrderBy(x => x.OrderDate) .ThenBy(x => x.Qty) .ToList(); } else { // Log the error or handle it appropriately throw new FormatException(OrderNumber is not in a valid integer format.); } }