static IFreeSql fsql = new FreeSql.FreeSqlBuilder()
    .UseConnectionString(FreeSql.DataType.MySql, connectionString)
    .UseAutoSyncStructure(true) //自动同步实体结构到数据库
    .Build(); //请务必定义成 Singleton 单例模式class Topic {
    [Column(IsIdentity = true, IsPrimary = true)]    public int Id { get; set; }    public int Clicks { get; set; }    public string Title { get; set; }    public DateTime CreateTime { get; set; }
}

更新指定列

fsql.Update<Topic>(1)
  .Set(a => a.CreateTime, DateTime.Now)
  .ExecuteAffrows();//UPDATE `Topic` SET `CreateTime` = '2018-12-08 00:04:59' 
//WHERE (`Id` = 1)

支持 Set() 多次，相当于拼接

更新指定列，累加

fsql.Update<Topic>(1)
  .Set(a => a.Clicks + 1)
  .Set(a => a.Time == DateTime.Now)
  .ExecuteAffrows();//UPDATE `Topic` SET `Clicks` = ifnull(`Clicks`,0) + 1, `Time` = now() 
//WHERE (`Id` = 1)

更新指定列，一次指定

fsql.Update<Topic>(1)
  .Set(a => new Topic
  {
    Clicks = a.Clicks + 1,
    Time = DateTime.Now
  })
  .ExecuteAffrows();//UPDATE `Topic` SET `Clicks` = ifnull(`Clicks`,0) + 1, `Time` = now() 
//WHERE (`Id` = 1)

根据 Dto 更新

fsql.Update<T>()
  .SetDto(new { title = "xxx", clicks = 2 })
  .Where(a => a.Id == 1)
  .ExecuteAffrows();//UPDATE `Topic` SET `Title` = @p_0, `Clicks` = @p_1//WHERE (Id = 1)

fsql.Update<T>()
  .SetDto(new Dictionary<string, object> { ["title"] = "xxx", ["clicks"] = 2 })
  .Where(a => a.Id == 1)
  .ExecuteAffrows();//效果同上

自定义SQL

fsql.Update<Topic>()
  .SetRaw("Title = @title", new { title = "新标题" })
  .Where("Id = @id", 1)
  .ExecuteAffrows();//UPDATE `Topic` SET Title = @title WHERE (Id = @id)

API