!IsNullOrWhiteSpace CLOB column bug

[Xor-el]

executing the query below

return await _db.Books.Where(x => !string.IsNullOrWhiteSpace(x.Metadata)).ToListAsync(cancellationToken);

against a CLOB column generates the following SQL

SELECT "b"."Id", "b"."AuthorId", "b"."Metadata", "b"."Title"
FROM "Books" "b"
WHERE (("b"."Metadata" IS NOT NULL) AND (LTRIM(RTRIM("b"."Metadata")) <> ''))

which throws ORA-00932: inconsistent datatypes: expected - got CLOB when run against the database.

note that the code generated by the inverse of the LINQ query (without the ! symbol before string.IsNullOrWhiteSpace) works ok.

Repro Project

https://github.com/Xor-el/EFCore-Oracle-Buggy-Demo/tree/!IsNullOrWhiteSpace-CLOB-column-bug

Provider and version information

EF Core version: Oracle.EntityFrameworkCore 7.21.8
Database provider: Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Target framework: .NET 6.0
Operating system: Windows 10
IDE: Visual Studio 2022 17.4.3

[alexkeh]

JSON is not currently supported in the Oracle EF Core 21.8 version. Oracle is planning to add this support soon.

This issue exists as a bug because the overarching enhancement has not been added. Bug 34989781 has been filed to track this issue. The parent enhancement request is #259.

[alexkeh]

Fixed with Oracle EF Core 8