平臺(tái)培訓(xùn)視頻04-mcs.framework dev data

1、DataAccess數(shù)據(jù)訪問(wèn)部分?jǐn)?shù)據(jù)庫(kù)連接和事務(wù)管理Sql語(yǔ)句構(gòu)造器ORMapping數(shù)據(jù)訪問(wèn)部分基本查詢語(yǔ)句Database db = DatabaseFactory.Create(DATextDB);Console.WriteLine(db.ExecuteScalar(CommandType.Text, SELECT COUNT(*) FROM USERS);疑問(wèn)？連接名稱是怎么定義的？誰(shuí)負(fù)責(zé)Open和Close連接？更復(fù)雜的查詢方式怎么實(shí)現(xiàn)？數(shù)據(jù)訪問(wèn)部分.Net Framework 2.0的事務(wù)管理提供本地事務(wù)管理，必要時(shí)使用DTC不需要編寫(xiě)Enterprise Service(Com+

2、)組件就可以支持分布式事務(wù)提供了隱式和顯式兩種方式使用事務(wù)數(shù)據(jù)訪問(wèn)部分隱式地使用事務(wù)using (TransactionScope scope = new TransactionScope(TransactionScopeOption.Required) Database db = DatabaseFactory.CreateDatabase(pubs); string mand = SELECT * FROM authors; DataSet ds = db.ExecuteDataSet( mand( mand); plete();線程上下文中保存Transaction對(duì)象。通過(guò)System

3、.Transactions.Transaction.Current數(shù)據(jù)訪問(wèn)部分void DoRootOP() using(TrsactionScope ts = new TrsactionScope() DoSubOP(); void DoSubOP() using(TrsactionScope ts = new TrsactionScope() ; 嵌套地使用隱式事務(wù)數(shù)據(jù)訪問(wèn)部分new TransactionScope(TransactionScopeOption.Required);TransactionScopeOptionsRequiredRequiresNewSuppress沒(méi)有類似

4、于Com+的Supported?隔離度Chaos， mitted， mitted，RepeatableRead，Serializable，Snapshot，Unspecified數(shù)據(jù)訪問(wèn)部分.Net Framework顯示地使用事務(wù)Transaction tx = new CommittableTransaction();SqlConnection myConnection = new SqlConnection(server=(local)SQLExpress;database=northwind.); mand mand = new mand();myConnection.Open();m

5、yConnection.EnlistTransaction(tx); /手工Enlisttry . mit();catch() tx.Rollback(); finally myConnection.Close();數(shù)據(jù)訪問(wèn)部分.Net Framework顯示地使用事務(wù)CommittableTransaction從Transaction類派生，擴(kuò)展了實(shí)現(xiàn)了Commit方法Transaction類沒(méi)有Commit，只有Rollback可序列化，可以跨越各種邊界支持異步事務(wù)提交生成以后，需要手工執(zhí)行Transaction.Current = new CommittableTransaction()

6、;數(shù)據(jù)訪問(wèn)部分.Net Framework在多線程中使用事務(wù)傳遞給其它線程的Transaction對(duì)象必須是Clone的(See Sample Code)Transaction.Current.DependentClone( plete)數(shù)據(jù)訪問(wèn)部分TransactionScope的問(wèn)題事務(wù)不是無(wú)代價(jià)的，可能會(huì)從本地事務(wù)提升到分布式事務(wù)using(TransactionScope ts = new TrsactionScope() DoInsert(“A”);DoInsert(“B”); plete(); void DoInsert(string data)DbConnection conn

7、= new SqlConnection(“connA”);conn.Open();數(shù)據(jù)訪問(wèn)部分使用DbContext管理連接using (DbContext context = DbContext.GetContext(DATextDB)Database db = DatabaseFactory.Create(DATextDB);db.ExecuteScalar(CommandType.Text,SELECT COUNT(*) FROM USERS);db.ExecuteScalar(CommandType.Text,“INSERT INTO USERS(USER_ID) VALUES(123

8、4);數(shù)據(jù)訪問(wèn)部分工作流組件消息處理組件其他應(yīng)用組件業(yè)務(wù)組件數(shù)據(jù)庫(kù)事務(wù)控制底層數(shù)據(jù)訪問(wèn)工具數(shù)據(jù)訪問(wèn)線程上下文存儲(chǔ)在線程上下文中的連接控制對(duì)象數(shù)據(jù)庫(kù)連接管理數(shù)據(jù)訪問(wèn)部分不會(huì)啟動(dòng)分布式事務(wù)using (DbContext context = DbContext.GetContext(DATextDB)using(TrsactionScope ts = new TrsactionScope() DoInsert(“A”);DoInsert(“B”); plete(); void DoInsert(string data)Database db = DatabaseFactory.Create(DAT

9、extDB);db.ExecuteScalar(CommandType.Text,“INSERT INTO USERS(USER_ID) VALUES(1234);數(shù)據(jù)訪問(wèn)部分會(huì)啟動(dòng)分布式事務(wù)using (DbContext context = DbContext.GetContext(“connA”)using(TrsactionScope ts = new TrsactionScope() DoInsert(“connA”);DoInsert(“connB”); plete(); void DoInsert(string connName)Database db = DatabaseFac

10、tory.Create(connName);db.ExecuteScalar(CommandType.Text,“INSERT INTO USERS(USER_ID) VALUES(1234);Data Source=.;Integrated Security=True;User Instance=True; Enlist=false providerName=System.Data.SqlClient數(shù)據(jù)訪問(wèn)部分基礎(chǔ)組件庫(kù)的事務(wù)管理使用TransactionScopeFactory創(chuàng)建ts缺省的隔離度是 mited(與new TransactionScope()不同)可以通過(guò)配置信息修改缺省隔離度和事務(wù)超時(shí)時(shí)間連接什么時(shí)候關(guān)閉？數(shù)據(jù)訪問(wèn)部分Sql語(yǔ)句的生成語(yǔ)句構(gòu)造器（InsertSqlClauseBuilder，Update，Where，OrderBy，In）基本構(gòu)造器(TSqlBuilder，PlSqlBuilder)ORMapping數(shù)據(jù)訪問(wèn)部分Sql語(yǔ)句構(gòu)造器數(shù)據(jù)訪問(wèn)部分ISqlBuilder的功能數(shù)據(jù)訪問(wèn)部分Sql語(yǔ)