.Net使用分表分库框架ShardingCore实现多字段分片_实用技巧_

 //这边演示不使用雪花id因为雪花id很难在演示中展示所以使用订单编号进行演示格式:yyyyMMddHHmmss+new Random().Next(0,10000).ToString().PadLeft(4,'0') var dateTime = new DateTime(2021, 11, 1); var order = await _myDbContext.Set().Where(o => o.OrderNo== 202112201900001111&&o.CreateTime< dateTime).FirstOrDefaultAsync();

 //请安装最新版本目前x.3.2.x+,第一个版本号6代表efcore的版本号 Install-Package ShardingCore -Version 6.3.2 Install-Package Microsoft.EntityFrameworkCore.SqlServer -Version 6.0.1

 public class Order { public string Id { get; set; } public string OrderNo { get; set; } public string Name { get; set; } public DateTime CreateTime { get; set; } }

 /// 
 /// 如果需要支持分表必须要实现 /// 
 public class DefaultDbContext:AbstractShardingDbContext,IShardingTableDbContext { public DefaultDbContext(DbContextOptions options) : base(options) { } protected override void OnModelCreating(ModelBuilder modelBuilder) { base.OnModelCreating(modelBuilder); modelBuilder.Entity(o => { o.HasKey(p => p.Id); o.Property(p => p.OrderNo).IsRequired().HasMaxLength(128).IsUnicode(false); o.Property(p => p.Name).IsRequired().HasMaxLength(128).IsUnicode(false); o.ToTable(nameof(Order)); }); } public IRouteTail RouteTail { get; set; } }

 public class OrderVirtualRoute : AbstractSimpleShardingMonthKeyDateTimeVirtualTableRoute { /// 
 /// 配置主分表字段是CreateTime,额外分表字段是OrderNo /// 
 ///  public override void Configure(EntityMetadataTableBuilder builder) { builder.ShardingProperty(o => o.CreateTime); builder.ShardingExtraProperty(o => o.OrderNo); } /// 
 /// 是否要在程序运行期间自动创建每月的表 /// 
 ///  public override bool AutoCreateTableByTime() { return true; } /// 
 /// 分表从何时起创建 /// 
 ///  public override DateTime GetBeginTime() { return new DateTime(2021, 9, 1); } /// 
 /// 配置额外分片路由规则 /// 
 ///  ///  ///  ///  public override Expression> GetExtraRouteFilter(object shardingKey, ShardingOperatorEnum shardingOperator, string shardingPropertyName) { switch (shardingPropertyName) { case nameof(Order.OrderNo): return GetOrderNoRouteFilter(shardingKey, shardingOperator); default: throw new NotImplementedException(shardingPropertyName); } } /// 
 /// 订单编号的路由 /// 
 ///  ///  ///  private Expression> GetOrderNoRouteFilter(object shardingKey, ShardingOperatorEnum shardingOperator) { //将分表字段转成订单编号 var orderNo = shardingKey?.ToString() ?? string.Empty; //判断订单编号是否是我们符合的格式 if (!CheckOrderNo(orderNo, out var orderTime)) { //如果格式不一样就直接返回false那么本次查询因为是and链接的所以本次查询不会经过任何路由,可以有效的防止恶意攻击 return tail => false; } //当前时间的tail var currentTail = TimeFormatToTail(orderTime); //因为是按月分表所以获取下个月的时间判断id是否是在临界点创建的 var nextMonthFirstDay = ShardingCoreHelper.GetNextMonthFirstDay(DateTime.Now); if (orderTime.AddSeconds(10) > nextMonthFirstDay) { var nextTail = TimeFormatToTail(nextMonthFirstDay); return DoOrderNoFilter(shardingOperator, orderTime, currentTail, nextTail); } //因为是按月分表所以获取这个月月初的时间判断id是否是在临界点创建的 if (orderTime.AddSeconds(-10) < ShardingCoreHelper.GetCurrentMonthFirstDay(DateTime.Now)) { //上个月tail var previewTail = TimeFormatToTail(orderTime.AddSeconds(-10)); return DoOrderNoFilter(shardingOperator, orderTime, previewTail, currentTail); } return DoOrderNoFilter(shardingOperator, orderTime, currentTail, currentTail); } private Expression> DoOrderNoFilter(ShardingOperatorEnum shardingOperator, DateTime shardingKey, string minTail, string maxTail) { switch (shardingOperator) { case ShardingOperatorEnum.GreaterThan: case ShardingOperatorEnum.GreaterThanOrEqual: { return tail => String.Compare(tail, minTail, StringComparison.Ordinal) >= 0; } case ShardingOperatorEnum.LessThan: { var currentMonth = ShardingCoreHelper.GetCurrentMonthFirstDay(shardingKey); //处于临界值 o=>o.time < [2021-01-01 00:00:00] 尾巴20210101不应该被返回 if (currentMonth == shardingKey) return tail => String.Compare(tail, maxTail, StringComparison.Ordinal) < 0; return tail => String.Compare(tail, maxTail, StringComparison.Ordinal) <= 0; } case ShardingOperatorEnum.LessThanOrEqual: return tail => String.Compare(tail, maxTail, StringComparison.Ordinal) <= 0; case ShardingOperatorEnum.Equal: { var isSame = minTail == maxTail; if (isSame) { return tail => tail == minTail; } else { return tail => tail == minTail || tail == maxTail; } } default: { return tail => true; } } } private bool CheckOrderNo(string orderNo, out DateTime orderTime) { //yyyyMMddHHmmss+new Random().Next(0,10000).ToString().PadLeft(4,'0') if (orderNo.Length == 18) { if (DateTime.TryParseExact(orderNo.Substring(0, 14), "yyyyMMddHHmmss", CultureInfo.InvariantCulture, DateTimeStyles.None, out var parseDateTime)) { orderTime = parseDateTime; return true; } } orderTime = DateTime.MinValue; return false; } }

 var order=new Order() //执行这边生成出来的id是2021-11-30 23:59:59.999.999 order.OrderNo=DateTime.Now.ToString("yyyyMMddHHmmss")+"xxx"; //business code //具体执行时间不确定,哪怕没有business code也没有办法保证两者生成的时间一致,当然如果你可以做到一致完全不需要这么复杂的编写 ............ //执行这边生成出来的时间是2021-12-01 00:00:00.000.000 order.CreateTime=DateTime.Now;

 ILoggerFactory efLogger = LoggerFactory.Create(builder => { builder.AddFilter((category, level) => category == DbLoggerCategory.Data
                
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