在构建Linq-to-Sql代码时强制实体框架不生成NCLOB（模型优先）

Question

I have a class with a nullable int property that that for filtering reasons, I need to convert to a string to do some comparisons. I have EF 6.1.2 installed, so using a .ToString() will work for that.

queryableData = queryableData.Where(a => 
    a.PropName.HasValue && a.PropName.Value.ToString().Contains("8675309"));

When examining the actual SQL being executed, the number is being CAST into an NCLOB type, which is resulting in the following error:

ORA-00932: inconsistent datatypes: expected NCHAR - got NCLOB

From what I've read, this is because Entity is unaware of the potential max size in this case, so it defaults to the largest option. I know with a string property that I would be able to denote a max size to help. Is there anything that I can do while keeping the property as an int to prevent the NCLOB's from being used? Or a way to use them while preventing this exception?

Some other notes:

• I'm on an Oracle System, so SqlFunctions.StringConvert is out.
• I'm on Odp.net version 12.x (related to this post ).
• The EF is a Model-First approach.
• The .Where() clause is being added to an AsQueryable(), so I can't do anything in memory.

Answer 1

I have the same problem with Oracle ( Oracle 11.2.02 and Oracle.ManagedDataAccess.12.2.1100 ) and Entity Framework ( EntityFramework.6.1.3 ).

This inside Linq code (the property "Id" is integer):

Material.Id.ToString()

Generates this SQL:

(CASE WHEN ("Extent3"."Material_Id" IS NULL) THEN N'' ELSE TO_NCLOB("Extent3"."Material_Id") END)

And the problem is TO_NCLOB , it should be TO_NCHAR

Solution
JonathanPeel comment
Install-Package EntityFramework.Functions