随笔- 119 文章- 1 评论- 2419 阅读- 77万

.NET 操作 TDengine .NET ORM

TDengine

是国内比较流的时序库之一，支持群集并且免费，在.NET中资料比较少，这篇文章主要介绍SqlSugar ORM来操作TDengine

优点：

1、SqlSugar支持ADO.NET操作来实现TDengine，并且支持了常用的时间函数、支持联表、分页和批量插入和删等操作

2、使用了原生连接（非http连接）保证了TDengine性能

TDengine 连接字符串

1	`Host=localhost;Port=6030;Username=root;Password=taosdata;Database=power`

TDengine 客户端SDK安装

当前程序需要安装Sdk才能连接数据库

https://docs.taosdata.com/connector

TDengine Nuegt安装

下面是NUGET安装

1 2	`SqlSugar.TDengineCore` `SqlSugarCore`

执行SQL

//建库
  db.Ado.ExecuteCommand("CREATE DATABASE IF NOT EXISTS power WAL_RETENTION_PERIOD 3600");
 
  //建超级表
  db.Ado.ExecuteCommand("CREATE STABLE IF NOT EXISTS  MyTable (ts TIMESTAMP, current FLOAT, voltage INT, phase FLOAT) TAGS (location BINARY(64), groupId INT)");
 
  //创建子表
  db.Ado.ExecuteCommand(@"create table IF NOT EXISTS  MyTable01 using MyTable tags('California.SanFrancisco',1)");
 
         
  //insert sql
  //db.Ado.ExecuteCommand(insrtSql);
 
  //查询子表
  var dt = db.Ado.GetDataTable("select * from MyTable01");
 
  //查询超级表
  var dt2 = db.Ado.GetDataTable("select * from MyTable");

单表查询

var list2 = db.Queryable<MyTable02>().Where(it => it.name == "测试2").ToList();
 var list22 = db.Queryable<MyTable02>().Where(it => it.voltage == 222).ToList();
 var list222 = db.Queryable<MyTable02>().Where(it => it.phase == 1.2).ToList();
 var list2222 = db.Queryable<MyTable02>().Where(it => it.isdelete == true).ToList();

联表查询

//联表查询:不支持left join只能这样
  var list101= db.Queryable<MyTable02, MyTable02>((x, y) => x.ts == y.ts)
               .Select((x,y) => new
               {
                   xts=x.ts,
                   yts=y.ts
               }).ToList();

函数用法

//模糊查询
 var list3 = db.Queryable<MyTable02>().Where(it => it.name.Contains("a")).ToList();
 
//时间差函数 
var list31 = db.Queryable<MyTable02>().Select(it =>
           new
           {
               diff = SqlFunc.DateDiff(DateType.Day, it.ts, DateTime.Now),
               time=it.ts
           }).ToList();
 
 //时间加1天
 var list32 = db.Queryable<MyTable02>().Select(it =>
             new
             {
                 addTime = SqlFunc.DateAdd(it.ts,1, DateType.Day),
                 oldime = it.ts
             }).ToList();
               
 //自定义函数:实现时间加1天
   var list33 = db.Queryable<MyTable02>().Select(it =>
             new
             {
                 addTime =SqlFunc.MappingColumn<DateTime>(" `ts`+1d "),
                 oldime = it.ts
             }).ToList();

分页查询

//分页
 var Count = 0;
var list4 = db.Queryable<MyTable02>().Where(it => it.voltage == 111)
              .ToPageList(1, 2, ref Count);

插入

超级表是不能插入的，我们只插入子表

//批量插入子表
  db.Insertable(GetInsertDatas()).ExecuteCommand();
  
  //子表实体
  public class MyTable02
  {
            [SugarColumn(IsPrimaryKey =true)]
            public DateTime ts { get; set; }
            public float current { get; set; }
            public bool isdelete { get; set; }
            public string name { get; set; }
            public int voltage { get; set; }
            public float phase { get; set; }
            [SugarColumn(IsOnlyIgnoreInsert =true,IsOnlyIgnoreUpdate =true)]//Tags字段禁止插入
            public string location { get; set; }
            [SugarColumn(IsOnlyIgnoreInsert = true, IsOnlyIgnoreUpdate = true)]//Tags字段禁止插入
            public int groupId { get; set; }
   }