EF Core 8.0 fails choosing the right constructor when creating entities from DB having multiple constructors

[SetTrend]

EF Core 8.0 Fails Choosing The Right Constructor When Creating Entities From DB Having Multiple Constructors

In my test case, the Model.Lookups.ProjectItem entity provides three different constructors, each validating their constructor arguments:

public ProjectItem(int id, bool isRequired, ItemDataType dataType);
public ProjectItem(int id, bool isRequired, ItemDataType dataType, byte precision);
public ProjectItem(int id, bool isRequired, ItemDataType dataType, KnowledgeCategory knowledgeCategory);

Current Situation

When reading data from the database, EF Core 8.0 does not use the proper constructor.

With this data:

Id	IsRequired	DataType	Precision	KnowledgeCategory
3	0	6		0

… EF Core 8.0 fails to select constructor #3. It, instead, chooses constructor #1.

Desired Situation

EF Core should select the right constructor from …

1. Number of non-nullable constructor parameters matching number of non-null column values,
   ordered by number of constructor parameters, descending
2. parameter data type
3. parameter name (if parameter data type alone cannot be uniquely matched)

If a row has more non-null columns than constructor parameters available, these surplus values ought to be set using property initializers then.

Minimum Reproducible Example

https://github.com/SetTrend/EFC-Constructor-MRE

[maumar]

Currently all constructor binding is static and non-configurable. Improvements to that area are tracked here: #10789

Also some documentation on what's currently possible: https://learn.microsoft.com/en-us/ef/core/modeling/constructors