EFCore 迁移命令移除外键

Posted 2020-12-19 lludcmmcdull

 

继承 MigrationsModelDiffer，重载 GetDifferences 并移除 ForeignKeys

    [System.Diagnostics.CodeAnalysis.SuppressMessage("Usage", "EF1001:Internal EF Core API usage.", Justification = "<挂起>")]
    public class MigrationsModelDifferWithoutForeignKey : MigrationsModelDiffer
    {
        public MigrationsModelDifferWithoutForeignKey
            ([NotNull] IRelationalTypeMappingSource typeMappingSource,
            [NotNull] IMigrationsAnnotationProvider migrationsAnnotations,
            [NotNull] IChangeDetector changeDetector,
            [NotNull] IUpdateAdapterFactory updateAdapterFactory,
            [NotNull] CommandBatchPreparerDependencies commandBatchPreparerDependencies)
            : base(typeMappingSource, migrationsAnnotations, changeDetector, updateAdapterFactory, commandBatchPreparerDependencies)
        {
        }

        public override IReadOnlyList<MigrationOperation> GetDifferences(IModel source, IModel target)
        {
            var operations = base.GetDifferences(source, target);

            foreach (var operation in operations.OfType<CreateTableOperation>())
                operation.ForeignKeys?.Clear();

            return operations;
        }
    }

 

使用时，替换服务即可：

　　services.AddDbContext<MyDbContext>(options =>
　　{
　　　　options.UseSqlServer(Default);
　　　　options.ReplaceService<IMigrationsModelDiffer, MigrationsModelDifferWithoutForeignKey>();
　　});