Databases
StackOverflow2013
Postsdbo
POWhy am I getting a "Nullable object must have a value" exception when I'm using Condition?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POWhy am I getting a "Nullable object must have a value" exception when I'm using Condition?
    primarykey
    data
    text
    <p>I'm getting a "Nullable object must have a value" in the example code below. Why do I need the following fix to make this work:</p> <pre><code>.ForMember(dest =&gt; dest.ShirtColor, dest =&gt; dest.MapFrom(src =&gt; src.ShirtColor != null ? new OptionSetValue((int) src.ShirtColor) : null)) </code></pre> <pre class="lang-cs prettyprint-override"><code>AutoMapper.Mapper.CreateMap&lt;PersonA, PersonB&gt;() .ForMember(dest =&gt; dest.FirstName, dest =&gt; dest.MapFrom(src =&gt; src.FirstName)) .ForMember(dest =&gt; dest.LastName, dest =&gt; dest.MapFrom(src =&gt; src.LastName)) // Condition to avoid overwriting existing data!!! .ForMember(dest =&gt; dest.ShirtColor, dest =&gt; dest.Condition(src =&gt; src.ShirtColor != null)) .ForMember(dest =&gt; dest.ShirtColor, dest =&gt; dest.MapFrom( src =&gt; new OptionSetValue((int)src.ShirtColor))) // Fix that should not be needed due to condition: //.ForMember(dest =&gt; dest.ShirtColor, // dest =&gt; dest.MapFrom( // src =&gt; src.ShirtColor != null // ? new OptionSetValue((int) src.ShirtColor) // : null)); PersonA source = new PersonA(); source.FirstName = "Thomas"; source.LastName = "Jefferson"; source.ShirtColor = null; // nullable int PersonB destination = new PersonB(); destination.FirstName = "Thomas"; destination.LastName = "Jefferson"; destination.ShirtColor = new OptionSetValue(4); // Results in: "Nullable object must have a value" despite the fact that // condition should have been met! Mapper.Map&lt;PersonA, PersonB&gt;(source, destination); Debug.Assert(destination.ShirtColor != null); Console.WriteLine("Our existing data was not overwritten!!"); Console.WriteLine("Hit enter to exit"); Console.ReadLine(); </code></pre> <p>Here is how OptionSet is defined: public class OptionSetValue { public OptionSetValue(){}</p> <pre class="lang-cs prettyprint-override"><code> public OptionSetValue(int value) { Number = value; } public int Number { get; set; } } </code></pre>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USDavid Yates
    1. USDavid Yates
    plurals
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POWhy am I getting a "Nullable object must have a value" exception when I'm using Condition?
      1. This table or related slice is empty.
      1. VTApproveEditSuggestion
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload