Possible to set column ordering in Entity Framework

问题

Is there any possible configuration to set database column ordering in entity framework code first approach..?

All of my entity set should have some common fields for keeping recordinfo

public DateTime CreatedAt { get; set; }
public int CreatedBy { get; set; }
public DateTime ModifiedAt { get; set; }
public int ModifiedBy { get; set; }
public bool IsDeleted { get; set; }

I want to keep this fields at the end of the table. Is there any possible EF configuration that i can use to config this rather than keeping this fields at the end of my model class.

回答1:

I'm assuming you are using Entity Framework 6 since column ordering is not yet supported in EF Core.

You can use either data attributes or the fluent API to set column order.

To use a Data Attribute to set column order, reference System.ComponentModel.DataAnnotations and use the ColumnAttribute. You can also set the column name with this attribute if you want it to differ from the property name.

[Column("CreatedAt", Order=0)]
public DateTime CreatedAt { get; set; }
[Column("CreatedBy", Order=1)]
public int CreatedBy { get; set; }

Note the Order parameter is zero-based.

See also: http://www.entityframeworktutorial.net/code-first/column-dataannotations-attribute-in-code-first.aspx

Alternatively, you can use the Fluent API in the OnModelCreating method in your DbContext class:

protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
    //Configure Column
    modelBuilder.Entity<EntityClass>()
                .Property(p => p.CreatedAt)
                .HasColumnOrder(0);
}

See also: http://www.entityframeworktutorial.net/code-first/configure-property-mappings-using-fluent-api.aspx

This way is a bit more verbose but you can have a more bit control over what's happening.

回答2:

Just use:

using System.ComponentModel.DataAnnotations.Schema;

Code:

[DisplayColumn("Name" , Order = 1)]
public int UserName { get; set; }

Notice: column order by default takes a big number so if you ordered only this column it will be first one in the table unless you ordered another column with a lower order number which is in this case : 0

来源：https://stackoverflow.com/questions/43246727/possible-to-set-column-ordering-in-entity-framework