EFSQLserver

2022-10-27 21:27:39

１．增加一条烽据

FLYNEWQKEntities dataContext = new FLYNEWQKEntities();
Log log = new Log();
log.Data1 = "tes";
dataContext.Log.Add(log);
dataContext.SaveChanges();

２．修改

FLYNEWQKEntities dataContext = new FLYNEWQKEntities();
Log log = dataContext.Log.Where(t => t.AutoID == 1).Take(1).Single();
log.Data2 = "33";
dataContext.SaveChanges();

3.删除

FLYNEWQKEntities dataContext = new FLYNEWQKEntities();
Log log = dataContext.Log.Where(t => t.AutoID == 1).Take(1).Single();
dataContext.Log.Remove(log);
dataContext.SaveChanges();

4. 列表

FLYNEWQKEntities dataContext = new FLYNEWQKEntities();

var v2 = from t in dataContext.T2_Elderly
join t0 in dataContext.T1_Set_CareLevel on t.CareLevelID equals t0.CareLevelID.ToString() //new { CareLevelID = t.CareLevelID } equals new { CareLevelID = t0.CareLevelID.ToString() }
select t0;
this.gridControl1.DataSource = v2.ToList();

5.事务

//事务
FLYNEWQKEntities dataContext = new FLYNEWQKEntities();
try
{

using (TransactionScope scope = new TransactionScope())
{
//Do something with context1
//Do something with context2
Log log = new Log();
log.Data1 = "tes";
dataContext.Log.Add(log);

//Save and discard changes
dataContext.SaveChanges();

Log log1 = dataContext.Log.Where(t => t.AutoID == log.AutoID).Take(1).Single();
log.Data2 = "33";
//Save and discard changes
dataContext.SaveChanges();
//throw new Exception("dddd");

//if we get here things are looking good.
//scope.Complete();
}
}
catch (Exception ex) {
MessageBox.Show(ex.ToString());
}

6.事务

FLYNEWQKEntities dataContext = new FLYNEWQKEntities();
//if (dataContext.Database.Connection != null)
//{
// dataContext.Database.Connection.Open();
//}
System.Data.Entity.DbContextTransaction tran = dataContext.Database.BeginTransaction();

try
{

Log log = new Log();
log.Data1 = "tes";
dataContext.Log.Add(log);

//Save and discard changes
dataContext.SaveChanges();

Log log1 = dataContext.Log.Where(t => t.AutoID == log.AutoID).Take(1).Single();
log.Data2 = "33";
//Save and discard changes
dataContext.SaveChanges();

//throw new Exception("dddd");
tran.Commit();
MessageBox.Show("保存成功！");
base.Close();

}
catch (Exception ex)
{
tran.Rollback();
MessageBox.Show(ex.Message);
}

7. 函数

https://msdn.microsoft.com/zh-cn/library/dd456847.aspx

http://www.dotblogs.com.tw/programlin/archive/2010/12/16/20179.aspx

1.Model-Defined Functions的定義是在Conceptual Model,而UDF需定義在Storage Model.
而設定的就如同EF設計stored procedure一樣,只是在一些參數上有所不同,但不幸的VS內建的EDM tools只能設計stored procedure

而無法定義UDF,所以請依上篇文章做法手動用XML Editor開啟EDM File.開啟後在<edmx:StorageModels>區段後加上

這邊的XML跟上篇文章很像,差異點在於UDF是定義於Storage Model故所有的資料型別都是sql type,這邊就不再多加說明了,紅字以外的描述都直接套用即可.

2.修改完 EDM後一樣的如同Model-Defined Functions上篇文章中的步驟二也必須在程式端定義一個類別來供給LINQ套用唯一的差別在於EdmFunctionAttribute的第一個參數namespace

改為EDM Storage Model區段中的namespace,可以在<edmx:StorageModels>後的<Schema Namespace="TestModel.Store" ../>取得
故在程式最後修改如下

要示写到静态类,中用静态函数的来写

public static class DbFunctions
{
//[EdmFunction("FLYNEWQKModel.Store", "fun_GetPY" )]
[DbFunction("FLYNEWQKModel.Store", "fun_GetPY")]
public static string fun_GetPY(string Str)
{
throw new NotSupportedException("Direct calls are not supported.");
}

[DbFunction("FLYNEWQKModel.Store", "fun_GetFeeCount")]

public static decimal? fun_GetFeeCount(string ElderlyID, DateTime Time1)
{
throw new NotSupportedException("Direct calls are not supported.");
}

[DbFunction("FLYNEWQKModel.Store", "fun_GetHYAmount")]
public static decimal? fun_GetHYAmount(string FZHNumber)
{
throw new NotSupportedException("Direct calls are not supported.");
}

}

在<edmx:StorageModels> 段增加对函数的定义

var v1 = from c in dataContext.T2_Elderly select new { c.ElderlyName, a = SqlFunctions.GetDate(), b = DbFunctions.fun_GetPY(c.ElderlyName), c = DbFunctions.fun_GetFeeCount(c.ElderlyID, SqlFunctions.GetDate().Value), d = DbFunctions.fun_GetHYAmount(c.ElderlyID) };

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