如何根据子集合中的值 select 对象？

Question

I have a list of Documents. A Document is like this:

class Document
{
    string Name;
    string Description;
    List<Page> Pages;
}

A Page is like this:

class Page
{
    string OCR;
}

What would be the following query in fluent LINQ against ef core 5?: I want to get all the document where "text" is in Name, or Description or OCR.

Is it possible to get the documents with a single fluent LINQ query? I came up with this, but I don't know how to add the OCR bit:

Documents.Where (   
                    x =>    x.Name.ToUpper ().Contains (text) 
                    ||      x.Description.ToUpper ().Contains (text)
                ).ToList ();

I know I could add a property on the Document like OCR, retrieve all the documents and then, in memory return all the OCR text from pages and then in the query do something like

Documents.Where (   
                    x =>    x.Name.ToUpper ().Contains (text) 
                    ||      x.Description.ToUpper ().Contains (text)
                    ||      x.OCR.ToUpper ().Contains (text)
                ).ToList ();

and that there could be other solutions, but I'd like to know if it's possible to do it in LINQ alone and against the database.

Thanks in advance!

Answer 1

You can simply include the Pages as a condition, which should translate properly in EF's query translation.

Here's an example, with example data:

var Documents = new List<Document>()
    {
        new Document
        {
            Name = "nottext",
            Description = "nottext",
            Pages = new List<Page>
            {
                new Page
                {
                    OCR = "text"
                }
            }
        },
        new Document
        {
            Name = "nottext",
            Description = "nottext",
            Pages = new List<Page>
            {
                new Page
                {
                    OCR = "text"
                }
            }
        }
    };

Documents.Where(d =>
       d.Name.Contains("text", StringComparison.OrdinalIgnoreCase)
    || d.Description.Contains("text", StringComparison.OrdinalIgnoreCase)
    || d.Pages.Any(p => p.OCR.Contains("text", StringComparison.OrdinalIgnoreCase)));