[Entity Framework Core] How to specify columns with variables in a Where statement [ASP.NET Core]

Hello, this is Hase from the System Development Department

I recently started developing with ASP.NET Core again, and
column names using variables when retrieving
specify

Introduction

First, let's say you have table data like this:

Accounts

*This is test data andthiswas extracted from

I would like to extract records from this data by specifying the columns and values

The usual way

In the normal way, you cannot specify columns dynamically, so the code will look like this:

string columnName = "LastName"; // Column name string value = "Hatayama"; // Search value // Extract records from the specified column name and value var query = context.Accounts; switch (columnName) { // When the NickName column is specified case "NickName": query = query.Where(c => c.NickName== value); break; // When the LastName column is specified case "LastName": query = query.Where(c => c.LastName== value); break; // When the FirstName column is specified case "FirstName": query = query.Where(c => c.FirstName == value); break; } var account = query.FirstOrDefault();

This results in a very redundant code, where each column name is compared with a case in the switch statement

Specifying column names using variables

However, Entity Framework Core has a way to dynamically specify column names!
That'sthe EF.Property methodcalled
This is a great tool that allows you to dynamically specify properties (column names) as arguments.

If you actually modify the previous code to use this method,

string columnName = "FirstName"; // Column name string value = "Sena"; // Search value // Extract records from the specified column name and value var account = context.Accounts.Where(c => EF.Property<string> (c, columnName) == value).FirstOrDefault();

And it can now be written in just one line without using a switch statement.
*You need to use Microsoft.Entity Framework Core.

summary

What did you think?

Personally, I found this to be a very useful feature.
I think it will be especially helpful when you want to implement a rich search function, so
please keep it in mind when using Entity Framework Core!

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