How to Convert Integers to Strings in LINQ to Entities Queries?

Linq to Entities Inquiries The trap of the integer converted into a string in the query

In Linq to Entities, converting an integer into a string may encounter unexpected challenges. This is particularly obvious when trying the string attribute value of integer attributes (such as contaltid) to the new object.

Common methods and their limitations

The first method, directly assigning C.CONTACTID to Value, will cause an error to "impossible to convert the type 'int' as 'String'".

The second method, using c.Contactid.tostring (), you will encounter another obstacle: "Linq to Entities does not support Tostring". This is because Tostring is a method that runs on the CLR object, not running on the Linq entity.

Elegant solutions using SQLFUNCTIONS

In Entity Framework (EF) 4.0 and higher versions, you can use Sqlfunctions.stringConvert method as a transformation solution. However, because there is no integer load, you must convert an integer to a dual -precision or decimal type:

This solution is effectively converted to a string in the Linq expression, allowing you to seamlessly map the Contractid to the value attribute.

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