Checking parameter for null causes incorrect projections translation #35518
Description
Bug description
This is a copy of npgsql/efcore.pg#3295
Hello,
When checking a joined entity for NULL the further projecting of joined table does not take effect causing always selecting all fields and all subsequent joins if any.
Suppose having following entity hierarchy: User -> Job? -> Address
class User {
public long Id { get; set; }
public long? JobId { get; set; }
// other unrelated properties
}
class Job {
public long Id { get; set; }
public long AddressId { get; set; }
// other unrelated properties
}
class Address {
public long Id { get; set; }
// other unrelated properties
}
The following linq query
var claim = await users
.Select(x => new
{
x.Id,
Job = x.Job == null ? null : new
{
x.Job.Id,
Address = new
{
x.Job.Address.Id,
x.Job.Address.Street
}
}
})
.Select(x => new
{
x.Id,
Job = x.Job == null ? null : new
{
x.Job.Id
}
})
.Where(x => x.Id == 14501)
.FirstOrDefaultAsync();
produces this sql:
SELECT c."Id", c0."Id", FALSE, c1."Id", c1."Street"
FROM "User" AS c
INNER JOIN "Job" AS c0 ON c."JobId" = c0."Id"
INNER JOIN "Address" AS c1 ON c0."AddressId" = c1."Id"
WHERE c."Id" = 14501
It includes join to Address table, even though it is not selected in the last Select method.
You may ask why doing consequent selects, the answer is the part before second select may come from elsewhere as IQueryable which you want to further narrow down.
Anyways, is that expected? And is it possible to workaround?
Your code
see descriptionStack traces
Verbose output
EF Core version
9.0.0
Database provider
Npgsql.EntityFrameworkCore.PostgreSQL.9.0.1
Target framework
No response
Operating system
MAC OS
IDE
Jetbrains Rider