Select All Rows Using Entity Framework

asp.netEntity Framework

asp.net Problem Overview


I'm trying to select all the rows out of a database using entity framework for manipulation before they're sent to the form

var ptx = [modelname].[tablename]();
ptx.[tablename].Select(????)

what goes in the ????

asp.net Solutions


Solution 1 - asp.net

I used the entitydatasource and it provide everything I needed for what I wanted to do.

_repository.[tablename].ToList();

Solution 2 - asp.net

Entity Framework has one beautiful thing for it, like :

var users = context.Users; 

This will select all rows in Table User, then you can use your .ToList() etc.


For newbies to Entity Framework, it is like :

PortalEntities context = new PortalEntities();
var users = context.Users;

This will select all rows in Table User

Solution 3 - asp.net

How about:

using (ModelName context = new ModelName())
{
    var ptx = (from r in context.TableName select r);
}

ModelName is the class auto-generated by the designer, which inherits from ObjectContext.

Solution 4 - asp.net

You can use this code to select all rows :

C# :

var allStudents = [modelname].[tablename].Select(x => x).ToList();

Solution 5 - asp.net

You can simply iterate through the DbSet context.tablename

foreach(var row in context.tablename)
  Console.WriteLn(row.field);

or to evaluate immediately into your own list

var allRows = context.tablename.ToList();

Solution 6 - asp.net

Old post I know, but using Select(x => x) can be useful to split the EF Core (or even just Linq) expression up into a query builder.

This is handy for adding dynamic conditions.

For example:

public async Task<User> GetUser(Guid userId, string userGroup, bool noTracking = false)
{
    IQueryable<User> queryable = _context.Users.Select(x => x);

    if(!string.IsNullOrEmpty(userGroup))
        queryable = queryable.Where(x => x.UserGroup == userGroup);

    if(noTracking)
        queryable = queryable.AsNoTracking();

    return await queryable.FirstOrDefaultAsync(x => x.userId == userId);
}

Solution 7 - asp.net

Here is a few ways to do it (Just assume I'm using Dependency Injection for the DbConext)

public class Example
{
    private readonly DbContext Context;

    public Example(DbContext context)
    {
        Context = context;
    }

    public DbSetSampleOne[] DbSamples { get; set; }

    public void ExampleMethod DoSomething()
    {
        // Example 1: This will select everything from the entity you want to select
        DbSamples = Context.DbSetSampleOne.ToArray();

        // Example 2: If you want to apply some filtering use the following example
        DbSamples = Context.DbSetSampleOne.ToArray().Where(p => p.Field.Equals("some filter"))
    
    }

Solution 8 - asp.net

If it's under a async method then use ToListAsync()

        public async Task<List<DocumentTypes>> GetAllDocumentTypes()
        {
            var documentTypes = await _context.DocumentTypes.ToListAsync();

            return documentTypes;
        }

Solution 9 - asp.net

You can use:

ptx.[tablename].Select( o => true)

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Content TypeOriginal AuthorOriginal Content on Stackoverflow
QuestionCallum LiningtonView Question on Stackoverflow
Solution 1 - asp.netCallum LiningtonView Answer on Stackoverflow
Solution 2 - asp.netIrfView Answer on Stackoverflow
Solution 3 - asp.netMike ChristensenView Answer on Stackoverflow
Solution 4 - asp.netzoheir mazView Answer on Stackoverflow
Solution 5 - asp.netavenmoreView Answer on Stackoverflow
Solution 6 - asp.netMark JohnsonView Answer on Stackoverflow
Solution 7 - asp.netChase CrawfordView Answer on Stackoverflow
Solution 8 - asp.netKushalSethView Answer on Stackoverflow
Solution 9 - asp.netGlaxalgView Answer on Stackoverflow