Question 418590 in PostgreSQL Question posted in
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Postgresql – how to set entity's property order to mapping migrations dbscript columns order?

1.I have a BaseModel class:

public class BaseModel : BaseDeletedModel
{
    [Key, Column(Order = 0), MaxLength(50), Required]
    public string ID { get; set; }
}


public class BaseDeletedModel
{
    [Column(Order = 100), DefaultValue(false)]
    public bool IsDeleted { get; set; }
}
  1. and then i create a bussiness class to inherit this base class:
public class Test: BaseModel
{
    [MaxLength(200), Required]
    public string Name { get; set; }
}

3.The script generated by the migration instruction is as follows:

columns: table => new
{
    id = table.Column<string>(type: "character varying(50)", maxLength: 50, nullable: false),
    is_deleted = table.Column<bool>(type: "boolean", nullable: false, defaultValue: false),
   
    name = table.Column<string>(type: "character varying(200)", maxLength: 200, nullable: false)
}

4.but i want the order is:
id
name
isdeleted

I don’t want to use the Fluent API to set it up like this:

modelBuilder.Entity<Test>().Property(e => e.ID).HasColumnOrder(0);
modelBuilder.Entity<Test>().Property(e => e.Name).xxxxxxxxxx;
modelBuilder.Entity<Test>().Property(e => e.IsDeleted).HasColumnOrder(100).HasDefaultValue(false);

just set in entity class,is there a good solution?

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    @Svyatoslav Danyliv

    Thanks,Your solution has completely opened up my thinking。

    But there is a small issue, the method of entityType.GetProperties() is sorted alphabetically，so it cannot export like this : BName ,AName

    public class Test: BaseModel
{
    public string BName { get; set; }

    public string AName { get; set; }
}

    because the basemodel's fileds have Column(Order = x) x=0 (...) x=100 so i resolve it at the last like this:

    var columnOrder = property.GetColumnOrder();
if (!columnOrder.HasValue)
{
    property.SetColumnOrder(1);
}

  2. 0

    You can define a custom extension method to sort properties in a specific order for all known entities:

    public static class ModelBuilderExtensions
{
    public static ModelBuilder ApplyCustomColumnsOrder<TFirst, TLast>(this ModelBuilder modelBuilder)
    {
        var first = typeof(TFirst);
        var last = typeof(TLast);

        foreach (var entityType in modelBuilder.Model.GetEntityTypes())
        {
            if (!first.IsAssignableFrom(entityType.ClrType)) 
                continue;

            var typeProperties = entityType.ClrType.GetProperties().ToList();
            var properties = entityType.GetProperties()
                .Select((prop, index) => (
                    index: prop.PropertyInfo == null ? index * 10000 : typeProperties.IndexOf(prop.PropertyInfo),
                    prop))
                .ToList();

            var sorted = properties
                .OrderBy(p =>
                    p.prop.PropertyInfo?.DeclaringType == first ? 0 : p.prop?.PropertyInfo?.DeclaringType == last ? 2 : 1)
                .ThenBy(p => p.index)
                .Select(x => x.prop)
                .ToList();

            for (var i = 0; i < sorted.Count; i++)
            {
                sorted[i].SetColumnOrder(i);
            }
        }

        return modelBuilder;
    }
}

    In the OnModelCreating method, you should call this extension method at the end of the method:

    protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    // Other existing configurations

    modelBuilder.ApplyCustomColumnsOrder<BaseModel, BaseDeletedModel>();
}
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