Compare DateOnly values with DateTime. Shouldn't it be possible?-CodePudding

Using .Net 6 and VS2022 , consider this code:

DateOnly dateOnly= new DateOnly(2022,12,24);
            DateTime dateTime = DateTime.Now;

            if (dateTime > dateOnly)
            {

            }

It will result this error:

Operator '>' cannot be applied to operands of type 'DateTime' and 'DateOnly'

Even there is no built-in property to get the DateOnly from a DateTime without coding some custom extension methods nor the DateOnly.Compare methods supports comparing to DateTime type. The story is the same for TimeOnly If I am not missing something, what is the correct way of comparing this two type?

Update:

Just found It is not even possible to use these type just like other types in the webapi query parameters! Also EF core 6 does not have build-in support for these types in SqlClient!
Maybe it would be better to delay using these types...

CodePudding user response：

You can use the following methods to convert either to DateOnly or to DateTime, depending on what you need in the end.

var d = DateOnly.FromDateTime(DateTime.Now);
var dt = d.ToDateTime(TimeOnly.MinValue); // or whatever time you want

CodePudding user response：

You can get the DateOnly from DateTime like this.

DateOnly dateOnly = DateOnly.FromDateTime(dateTime);

Then you can use the CompareTo method to compare both DateOnly.

Same concept is for TimeOnly, there is a TimeOnly.FromDateTime method.

CodePudding user response：

This can work but you need to do a little fandangling.

I.E. Convert either DateOnly or DateTime to string then convert it to the other format then use compare. Off the top of my head, I do not know the exact code but it will look like this:

DateOnly origDO;// = some value;
DateTime origDT;// = some value;

string dTString = origDT.ToString("yyyy-MM-dd HH:mm:ss");
DateOnly convertedDO = DateOnly.Parse(dTString);

//-1 = <, 0 = ==, 1 = >
DateOnly.Compare(origDO, convertedDO);

The best way, is probably to use the base conversions that gSharp showed and then use the default comparison that I showed.

Don't forget that you can always write your own comparison at any time. So, DateOnly.Day > DateTime.Day