Entity Framework Core添加唯一约束

            entityBuilder.HasIndex(g => g.GroupId)
                .IsUnique();

完全代码

 

        public GroupMappingMap(EntityTypeBuilder entityBuilder)
        {
            entityBuilder.ToTable("GroupMapping");

            entityBuilder.HasKey(g => g.Id);

            entityBuilder.HasIndex(g => g.GroupId)
                .IsUnique();
        }