没有实现强制级联删除

Question

我已经为三个 1:many 关系指定了级联删除，但它没有在数据库中设置它。以下是 Event 由 Campaign、County 或 State“拥有”的类。三者中仅一者。我在这里只展示活动，但其他人也有相同的代码。

public class Event
{
    public required User Owner { get; set; }
    public Campaign? Campaign { get; set; }
    public County? County { get; set; }
    public State? State { get; set; }
    // lots of other props...
}

public class Campaign
{
    public ICollection<Event> Events { get; set; }
    // lots of other props...
}

public class CampaignConfiguration : IEntityTypeConfiguration<Campaign>
{
    /// <inheritdoc />
    public void Configure(EntityTypeBuilder<Campaign> builder)
    {
        builder.HasIndex(new[] { "Name", "StateId" }).IsUnique();
        builder.HasIndex("StateId");
        builder.HasMany(x => x.Events)
            .WithOne(x => x.Campaign).OnDelete(DeleteBehavior.ClientCascade);
    }
}

并且在 migration.cs 中（注意用户有一个事件集合，因此它被设置为级联删除）

migrationBuilder.CreateTable(
    name: "Events",
    columns: table => new
    {
        // all the columns
    },
    constraints: table =>
    {
        table.PrimaryKey("PK_Events", x => x.Id);
        table.ForeignKey(
            name: "FK_Events_Campaigns_CampaignId",
            column: x => x.CampaignId,
            principalTable: "Campaigns",
            principalColumn: "Id");
        table.ForeignKey(
            name: "FK_Events_Counties_CountyId",
            column: x => x.CountyId,
            principalTable: "Counties",
            principalColumn: "Id");
        table.ForeignKey(
            name: "FK_Events_States_StateId",
            column: x => x.StateId,
            principalTable: "States",
            principalColumn: "Id");
        table.ForeignKey(
            name: "FK_Events_Users_OwnerId",
            column: x => x.OwnerId,
            principalTable: "Users",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);
    });

为什么不把这些设置成级联删除？