How to Convert Date field to null while exporting to text file in C#

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Hi All,

I would like to convert Date field to null while exporting to text file.
Default date is '01/01/1753'.

if (invoice.ContractDatetime = "01/01/1753")
{
invoice.ContractDatetime = "";
}

I tried the above. it throws the following errors

Error 1 Cannot implicitly convert type 'string' to 'System.DateTime'
Error 2 Cannot implicitly convert type 'System.DateTime' to 'bool'
Error 3 Cannot convert null to 'System.DateTime' because it is a value type

Thanks in Advance.

Posted 28-Jun-14 19:50pm

Murugan.NM

Updated 28-Jun-14 20:02pm

v2

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PIEBALDconsult 29-Jun-14 1:55am

So? What's stopping you?

Murugan.NM 29-Jun-14 2:01am

Hi Sir,
if (invoice.ContractDatetime = "01/01/1753")
{
invoice.ContractDatetime = "";
}
I tried the above. it throws the following errors
Error 1 Cannot implicitly convert type 'string' to 'System.DateTime'
Error 2 Cannot implicitly convert type 'System.DateTime' to 'bool'
Error 3 Cannot convert null to 'System.DateTime' because it is a value type

2 solutions

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George Jonsson · Answer 1 · 2014-06-28T20:00:00

Solution 1

I assume you mean that you want to write null if the date is same as default.

This is one way to do it.

C#

DateTime defaultDate = DateTime.Parse("01/01/1753");

DateTime someDate1 = new DateTime();
if (someDate1.Date == defaultDate.Date)
  Console.WriteLine("null");
else
 Console.WriteLine(someDate1.ToString());

DateTime someDate2 = DateTime.Parse("01/01/1753");
if (someDate2.Date == defaultDate.Date)
  Console.WriteLine("null");
else
  Console.WriteLine(someDate2.ToString());

Posted 28-Jun-14 20:00pm

George Jonsson

Comments

Murugan.NM 29-Jun-14 2:43am

Hi Sir,

I tried but not it passed null value
What is wrong with i tried the following
DateTime defaultdate = DateTime.Parse("1753-01-01");

DateTime ContractDatetime = new DateTime();
if (invoice.ContractDatetime.Date == defaultdate.Date)
{
Console.WriteLine("null");
}
else
{
Console.WriteLine(invoice.ContractDatetime.ToString());
}

George Jonsson 29-Jun-14 5:16am

My code snippet was just an example.
How do you want the text file to look like in the different cases?

PIEBALDconsult · Answer 2 · 2014-06-29T06:48:00

Solution 3

Test against sqldatetime.minvalue[^]

Posted 29-Jun-14 6:48am

PIEBALDconsult