g.SimpleClient

Create DbContext

public class DbContext
{

        public SqlSugarClient Db;
        public DbContext()
        {
            Db = new SqlSugarClient(new ConnectionConfig()
            {
                ConnectionString = Config.ConnectionString,
                DbType = DbType.SqlServer,
                IsAutoCloseConnection = true,
                InitKeyType = InitKeyType.Attribute,
                AopEvents = new AopEvents()
                {
                    OnLogExecuting = (sql, p) =>
                    {
                        Console.WriteLine(sql);
                    }
                }
            });
        }
        public SimpleClient<Order> OrderDb => new SimpleClient<Order>(Db);
        public SimpleClient<OrderItem> OrderItemDb => new SimpleClient<OrderItem>(Db);
} 
public class Order
{
        [SqlSugar.SugarColumn(IsPrimaryKey = true, IsIdentity = true)]
        public int Id { get; set; }

        public string Name { get; set; }
        public decimal Price { get; set; }
        [SqlSugar.SugarColumn(IsNullable =true)]
        public DateTime CreateTime { get; set; }
}
[SqlSugar.SugarTable("OrderDetail")]
public class OrderItem
{
        [SqlSugar.SugarColumn(IsPrimaryKey =true, IsIdentity =true)]
        public int ItemId { get; set; }
        public int OrderId { get; set; }
        public decimal? Price { get; set; }
        [SqlSugar.SugarColumn(IsNullable = true)]
        public DateTime? CreateTime { get; set; }
   }

Use DbContext

DbContext context = new DbContext();
var orderDb = context.OrderDb;
//Select
var data1 = orderDb.GetById(1);
var data2 = orderDb.GetList();
var data3 = orderDb.GetList(it => it.Id == 1); 
var data4 = orderDb.GetSingle(it => it.Id == 1);
var p = new PageModel() { PageIndex = 1, PageSize = 2 };
var data5 = orderDb.GetPageList(it => it.Name == "xx", p);
Console.Write(p.PageCount);
var data6 = orderDb.GetPageList(it => it.Name == "xx", p, it => it.Name, OrderByType.Asc);
Console.Write(p.PageCount);
List<IConditionalModel> conModels = new List<IConditionalModel>();
conModels.Add(new ConditionalModel() { FieldName = "id", ConditionalType = ConditionalType.Equal, FieldValue = "1" });//id=1
var data7 = orderDb.GetPageList(conModels, p, it => it.Name, OrderByType.Asc);
orderDb.AsQueryable().Where(x => x.Id == 1).ToList();

//Insert
orderDb.Insert(insertObj);
orderDb.InsertRange(InsertObjs);
var id = orderDb.InsertReturnIdentity(insertObj);
orderDb.AsInsertable(insertObj).ExecuteCommand();


//Delete
orderDb.Delete(insertObj);
orderDb.DeleteById(1);
orderDb.DeleteById(new int[] { 1, 2 });
orderDb.Delete(it => it.Id == 1);
orderDb.AsDeleteable().Where(it => it.Id == 1).ExecuteCommand();

//Update
orderDb.Update(insertObj); 
orderDb.UpdateRange(InsertObjs); 
orderDb.Update(it => new Order() { Name = "a", }, it => it.Id == 1);
orderDb.AsUpdateable(insertObj).UpdateColumns(it=>new { it.Name }).ExecuteCommand();

3.Inherit DbContext

   OrderDal dal = new OrderDal();
   var data=dal.GetById(1);
   var list = dal.GetList();

    public class OrderDal : DbContext<Order>
    {
   
    }
    /// <summary>
    /// DbContext  Example 2
    /// </summary>
    /// <typeparam name="T"></typeparam>
    public class DbContext<T> where T : class, new()
    {

        public SqlSugarClient Db;
        public DbContext()
        {
            Db = new SqlSugarClient(new ConnectionConfig()
            {
                ConnectionString = Config.ConnectionString,
                DbType = DbType.SqlServer,
                IsAutoCloseConnection = true,
                InitKeyType = InitKeyType.Attribute,
                AopEvents = new AopEvents()
                {
                    OnLogExecuting = (sql, p) =>
                    {
                        Console.WriteLine(sql);
                    }
                }
            });
        }
        public SimpleClient<T> CurrentDb => new SimpleClient<T>(Db);
        public virtual T GetById(int id)
        {
            return CurrentDb.GetById(id);
        }
        public virtual List<T> GetList()
        {
            return CurrentDb.GetList();
        }
        public virtual bool Delete(int id)
        {
            return CurrentDb.DeleteById(id);
        }
    }