DxGrid.GroupBy(String) Method

Groups data by values of the specified column.

Namespace: DevExpress.Blazor

Assembly: DevExpress.Blazor.v24.2.dll

NuGet Package: DevExpress.Blazor

Declaration

public void GroupBy(
    string columnFieldName
)

Parameters

Name	Type	Description
columnFieldName	String	Specifies the name of the data source field that supplies data for the processed column. If the component does not contain the column that corresponds to the specified data field, an exception occurs.

Remarks

The GroupBy method allows you to group grid data in code regardless of the DxGrid.AllowGroup or DxGridDataColumn.AllowGroup property value.

The following code snippet uses different method overloads.

Razor

@using Microsoft.EntityFrameworkCore
@inject IDbContextFactory<NorthwindContext> NorthwindContextFactory
@implements IDisposable

<DxGrid Data="GridDataSource"
        ShowGroupPanel="true"
        CustomizeCellDisplayText="OnCustomizeCellDisplayText"
        @ref="@MyGrid">
    <Columns>
        <DxGridDataColumn FieldName="OrderDate"
                      DisplayFormat="d"
                      GroupInterval="GridColumnGroupInterval.DateMonth" />
        <DxGridDataColumn FieldName="Customer"
                      SortMode="GridColumnSortMode.DisplayText"
                      GroupInterval="GridColumnGroupInterval.DisplayText" />
        <DxGridDataColumn FieldName="Freight"
                      DisplayFormat="n2"/>
    </Columns>
</DxGrid>

<DxButton Click="@(() => MyGrid.GroupBy("OrderDate"))">Group by OrderDate</DxButton>
<DxButton Click="@(() => MyGrid.GroupBy("Customer", 0))">Group by Customer, Group Index = 0</DxButton>

@code {
    IGrid MyGrid { get; set; }
    object GridDataSource { get; set; }
    NorthwindContext Northwind { get; set; }

    protected override void OnInitialized() {
        Northwind = NorthwindContextFactory.CreateDbContext();
        GridDataSource = Northwind.Orders
            .Include(i => i.Customer)
            .Include(i => i.OrderDetails)
            .Include(i => i.ShipViaNavigation)
            .ToList();
    }

    void OnCustomizeCellDisplayText(GridCustomizeCellDisplayTextEventArgs e) {
        if (e.FieldName == "Customer") {
            var customer = (Customer)e.Value;
            e.DisplayText = $"{customer.CompanyName} ({customer.Country}, {customer.City})";
        }
    }

    public void Dispose() {
        Northwind?.Dispose();
    }
}

NorthwindContext.cs

using Microsoft.EntityFrameworkCore;
#nullable disable

namespace Grid.Northwind {
    public partial class NorthwindContext : DbContext {

        public NorthwindContext(DbContextOptions<NorthwindContext> options)
            : base(options) {
        }

        public virtual DbSet<Category> Categories { get; set; }
        public virtual DbSet<Customer> Customers { get; set; }
        public virtual DbSet<Invoice> Invoices { get; set; }
        public virtual DbSet<Order> Orders { get; set; }
        public virtual DbSet<OrderDetail> OrderDetails { get; set; }
        public virtual DbSet<Product> Products { get; set; }
        public virtual DbSet<Shipper> Shippers { get; set; }
        public virtual DbSet<Supplier> Suppliers { get; set; }
        public virtual DbSet<Employee> Employees { get; set; }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder) {
            if(!optionsBuilder.IsConfigured) {
                optionsBuilder.UseSqlServer("Server=.\\sqlexpress;Database=Northwind;Integrated Security=true");
            }
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder) {
            modelBuilder.HasAnnotation("Relational:Collation", "SQL_Latin1_General_CP1_CI_AS");
            modelBuilder.Entity<Category>(entity => {
                entity.HasIndex(e => e.CategoryName, "CategoryName");
                entity.Property(e => e.CategoryId).HasColumnName("CategoryID");
                entity.Property(e => e.CategoryName)
                    .IsRequired()
                    .HasMaxLength(15);
                entity.Property(e => e.Description).HasColumnType("ntext");
                entity.Property(e => e.Picture).HasColumnType("image");
            });
            modelBuilder.Entity<Customer>(entity => {
                entity.HasIndex(e => e.City, "City");
                entity.HasIndex(e => e.CompanyName, "CompanyName");
                entity.HasIndex(e => e.PostalCode, "PostalCode");
                entity.HasIndex(e => e.Region, "Region");
                entity.Property(e => e.CustomerId)
                    .HasMaxLength(5)
                    .HasColumnName("CustomerID")
                    .IsFixedLength(true);
                entity.Property(e => e.Address).HasMaxLength(60);
                entity.Property(e => e.City).HasMaxLength(15);
                entity.Property(e => e.CompanyName)
                    .IsRequired()
                    .HasMaxLength(40);
                entity.Property(e => e.ContactName).HasMaxLength(30);
                entity.Property(e => e.ContactTitle).HasMaxLength(30);
                entity.Property(e => e.Country).HasMaxLength(15);
                entity.Property(e => e.Fax).HasMaxLength(24);
                entity.Property(e => e.Phone).HasMaxLength(24);
                entity.Property(e => e.PostalCode).HasMaxLength(10);
                entity.Property(e => e.Region).HasMaxLength(15);
            });
            modelBuilder.Entity<Invoice>(entity => {
                entity.HasNoKey();
                entity.ToView("Invoices");
                entity.Property(e => e.Address).HasMaxLength(60);
                entity.Property(e => e.City).HasMaxLength(15);
                entity.Property(e => e.Country).HasMaxLength(15);
                entity.Property(e => e.CustomerId)
                    .HasMaxLength(5)
                    .HasColumnName("CustomerID")
                    .IsFixedLength(true);
                entity.Property(e => e.CustomerName)
                    .IsRequired()
                    .HasMaxLength(40);
                entity.Property(e => e.ExtendedPrice).HasColumnType("money");
                entity.Property(e => e.Freight).HasColumnType("money");
                entity.Property(e => e.OrderDate).HasColumnType("datetime");
                entity.Property(e => e.OrderId).HasColumnName("OrderID");
                entity.Property(e => e.PostalCode).HasMaxLength(10);
                entity.Property(e => e.ProductId).HasColumnName("ProductID");
                entity.Property(e => e.ProductName)
                    .IsRequired()
                    .HasMaxLength(40);
                entity.Property(e => e.Region).HasMaxLength(15);
                entity.Property(e => e.RequiredDate).HasColumnType("datetime");
                entity.Property(e => e.Salesperson)
                    .IsRequired()
                    .HasMaxLength(31);
                entity.Property(e => e.ShipAddress).HasMaxLength(60);
                entity.Property(e => e.ShipCity).HasMaxLength(15);
                entity.Property(e => e.ShipCountry).HasMaxLength(15);
                entity.Property(e => e.ShipName).HasMaxLength(40);
                entity.Property(e => e.ShipPostalCode).HasMaxLength(10);
                entity.Property(e => e.ShipRegion).HasMaxLength(15);
                entity.Property(e => e.ShippedDate).HasColumnType("datetime");
                entity.Property(e => e.ShipperName)
                    .IsRequired()
                    .HasMaxLength(40);
                entity.Property(e => e.UnitPrice).HasColumnType("money");
            });
            modelBuilder.Entity<Order>(entity => {
                entity.HasIndex(e => e.CustomerId, "CustomerID");
                entity.HasIndex(e => e.CustomerId, "CustomersOrders");
                entity.HasIndex(e => e.EmployeeId, "EmployeeID");
                entity.HasIndex(e => e.EmployeeId, "EmployeesOrders");
                entity.HasIndex(e => e.OrderDate, "OrderDate");
                entity.HasIndex(e => e.ShipPostalCode, "ShipPostalCode");
                entity.HasIndex(e => e.ShippedDate, "ShippedDate");
                entity.HasIndex(e => e.ShipVia, "ShippersOrders");
                entity.Property(e => e.OrderId).HasColumnName("OrderID");
                entity.Property(e => e.CustomerId)
                    .HasMaxLength(5)
                    .HasColumnName("CustomerID")
                    .IsFixedLength(true);
                entity.Property(e => e.EmployeeId).HasColumnName("EmployeeID");
                entity.Property(e => e.Freight)
                    .HasColumnType("money")
                    .HasDefaultValueSql("((0))");
                entity.Property(e => e.OrderDate).HasColumnType("datetime");
                entity.Property(e => e.RequiredDate).HasColumnType("datetime");
                entity.Property(e => e.ShipAddress).HasMaxLength(60);
                entity.Property(e => e.ShipCity).HasMaxLength(15);
                entity.Property(e => e.ShipCountry).HasMaxLength(15);
                entity.Property(e => e.ShipName).HasMaxLength(40);
                entity.Property(e => e.ShipPostalCode).HasMaxLength(10);
                entity.Property(e => e.ShipRegion).HasMaxLength(15);
                entity.Property(e => e.ShippedDate).HasColumnType("datetime");
                entity.HasOne(d => d.Customer)
                    .WithMany(p => p.Orders)
                    .HasForeignKey(d => d.CustomerId)
                    .HasConstraintName("FK_Orders_Customers");
                entity.HasOne(d => d.ShipViaNavigation)
                    .WithMany(p => p.Orders)
                    .HasForeignKey(d => d.ShipVia)
                    .HasConstraintName("FK_Orders_Shippers");
            });
            modelBuilder.Entity<OrderDetail>(entity => {
                entity.HasKey(e => new { e.OrderId, e.ProductId })
                    .HasName("PK_Order_Details");
                entity.ToTable("Order Details");
                entity.HasIndex(e => e.OrderId, "OrderID");
                entity.HasIndex(e => e.OrderId, "OrdersOrder_Details");
                entity.HasIndex(e => e.ProductId, "ProductID");
                entity.HasIndex(e => e.ProductId, "ProductsOrder_Details");
                entity.Property(e => e.OrderId).HasColumnName("OrderID");
                entity.Property(e => e.ProductId).HasColumnName("ProductID");
                entity.Property(e => e.Quantity).HasDefaultValueSql("((1))");
                entity.Property(e => e.UnitPrice).HasColumnType("money");
                entity.HasOne(d => d.Order)
                    .WithMany(p => p.OrderDetails)
                    .HasForeignKey(d => d.OrderId)
                    .OnDelete(DeleteBehavior.ClientSetNull)
                    .HasConstraintName("FK_Order_Details_Orders");
                entity.HasOne(d => d.Product)
                    .WithMany(p => p.OrderDetails)
                    .HasForeignKey(d => d.ProductId)
                    .OnDelete(DeleteBehavior.ClientSetNull)
                    .HasConstraintName("FK_Order_Details_Products");
            });
            modelBuilder.Entity<Product>(entity => {
                entity.HasIndex(e => e.CategoryId, "CategoriesProducts");
                entity.HasIndex(e => e.CategoryId, "CategoryID");
                entity.HasIndex(e => e.ProductName, "ProductName");
                entity.HasIndex(e => e.SupplierId, "SupplierID");
                entity.HasIndex(e => e.SupplierId, "SuppliersProducts");
                entity.Property(e => e.ProductId).HasColumnName("ProductID");
                entity.Property(e => e.CategoryId).HasColumnName("CategoryID");
                entity.Property(e => e.ProductName)
                    .IsRequired()
                    .HasMaxLength(40);
                entity.Property(e => e.QuantityPerUnit).HasMaxLength(20);
                entity.Property(e => e.ReorderLevel).HasDefaultValueSql("((0))");
                entity.Property(e => e.SupplierId).HasColumnName("SupplierID");
                entity.Property(e => e.UnitPrice)
                    .HasColumnType("money")
                    .HasDefaultValueSql("((0))");
                entity.Property(e => e.UnitsInStock).HasDefaultValueSql("((0))");
                entity.Property(e => e.UnitsOnOrder).HasDefaultValueSql("((0))");
                entity.HasOne(d => d.Category)
                    .WithMany(p => p.Products)
                    .HasForeignKey(d => d.CategoryId)
                    .HasConstraintName("FK_Products_Categories");
                entity.HasOne(d => d.Supplier)
                    .WithMany(p => p.Products)
                    .HasForeignKey(d => d.SupplierId)
                    .HasConstraintName("FK_Products_Suppliers");
            });
            modelBuilder.Entity<Shipper>(entity => {
                entity.Property(e => e.ShipperId).HasColumnName("ShipperID");
                entity.Property(e => e.CompanyName)
                    .IsRequired()
                    .HasMaxLength(40);
                entity.Property(e => e.Phone).HasMaxLength(24);
            });
            modelBuilder.Entity<Supplier>(entity => {
                entity.HasIndex(e => e.CompanyName, "CompanyName");
                entity.HasIndex(e => e.PostalCode, "PostalCode");
                entity.Property(e => e.SupplierId).HasColumnName("SupplierID");
                entity.Property(e => e.Address).HasMaxLength(60);
                entity.Property(e => e.City).HasMaxLength(15);
                entity.Property(e => e.CompanyName)
                    .IsRequired()
                    .HasMaxLength(40);
                entity.Property(e => e.ContactName).HasMaxLength(30);
                entity.Property(e => e.ContactTitle).HasMaxLength(30);
                entity.Property(e => e.Country).HasMaxLength(15);
                entity.Property(e => e.Fax).HasMaxLength(24);
                entity.Property(e => e.HomePage).HasColumnType("ntext");
                entity.Property(e => e.Phone).HasMaxLength(24);
                entity.Property(e => e.PostalCode).HasMaxLength(10);
                entity.Property(e => e.Region).HasMaxLength(15);
            });
            modelBuilder.Entity<Employee>(entity => {
                entity.HasIndex(e => e.EmployeeId, "EmployeeId");
                entity.HasIndex(e => e.LastName, "LastName");
                entity.HasIndex(e => e.FirstName, "FirstName");
                entity.HasIndex(e => e.Title, "Title");
                entity.HasIndex(e => e.BirthDate, "BirthDate");
                entity.HasIndex(e => e.HireDate, "HireDate");
                entity.HasIndex(e => e.Notes, "Notes");
            });
            OnModelCreatingPartial(modelBuilder);
        }

        partial void OnModelCreatingPartial(ModelBuilder modelBuilder);
    }
}

Program.cs

using Microsoft.EntityFrameworkCore;
// ...
builder.Services.AddDbContextFactory<NorthwindContext>((sp, options) => {
    var env = sp.GetRequiredService<IWebHostEnvironment>();
    var dbPath = Path.Combine(env.ContentRootPath, "Northwind-5e44b51f.mdf");
    options.UseSqlServer("Server=(localdb)\\MSSQLLocalDB;Integrated Security=true;AttachDbFileName=" + dbPath);
});

Watch Video: Grid - Group Data

For more information about data grouping in the Grid component, refer to the following topic: Group Data in Blazor Grid.

Implements

GroupBy(String)