Enterprise Library1.0 -- DataAccess Application Block

技术2022-05-11 66

Enterprise Library 对大家来说应该不陌生,很早我就听说了这个东西,但一直没有时间来学习,最近终于抽出时间来学习 Enterprise Library,现在就把我学习过程中的一些实例发上来,供大家参考. Enterprise Library现在已经有2.0版本了,但我也是后来才看到的,其他的就不多说了,先说1.0里面的Data Access Application Block,以后有时间在研究2.0. 本来先看的是其中的Configuration Application Block,但我在Web项目中调试写入XML时总是不能成功,后来查资料得知Web项目中的config文件不能通过程序来修改或创建,不知道是否确有此事,还望高手指点,另外还不明白的是 Configuration Application Block在我们实际项目的开发中能起到什么样的作用,昨天也没想通. 好了,我们来看看Data Access Application Block 吧,首先我们看一下如何用 Enterprise Library 提供的配置工具来创建一个数据库实例.首先我们应该新建我们所需项目,然后在 Enterprise Library的安装目录的Bin目录中找到EntLibConfig.exe文件,双击打开,并选择File-->Open Application,打开刚刚新建项目的Web.Config文件,如下:

然后,右键单击Application,选择New--> DataAccess Application Block,如下图: 然后会自动在Data Access Block 节点下生成三个Connection String(保存新建的数据库实例的连接字符串信息),DataBaseInstance(此节点存放数据库实例名以及其他相关信息),DataBase Types(节点存放数据库类型,如Sql Server 或 Oracle等).接着我们在 Connection String 下的 Sql Connection String 下配置好我们的数据库连接信息(包括Server,Database,uid,pwd等). 上面所说的都配置好了以后,我们就可以点击 File-->Save All或Ctrl + Shift + S,如果配置没有错误的话,就会在你的项目中生成一个dataConfiguration.config文件,内容如下:

<? xml version="1.0" encoding="utf-8" ?> < dataConfiguration > < xmlSerializerSection type ="Microsoft.Practices.EnterpriseLibrary.Data.Configuration.DatabaseSettings, Microsoft.Practices.EnterpriseLibrary.Data, Version=1.1.0.0, Culture=neutral, PublicKeyToken=null" > < enterpriseLibrary .databaseSettings xmlns:xsd ="http://www.w3.org/2001/XMLSchema" xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" defaultInstance ="EnterpriseLibrary" xmlns ="http://www.microsoft.com/practices/enterpriselibrary/08-31-2004/data" > < databaseTypes > < databaseType name ="Sqlserver" type ="Microsoft.Practices.EnterpriseLibrary.Data.Sql.SqlDatabase, Microsoft.Practices.EnterpriseLibrary.Data, Version=1.1.0.0, Culture=neutral, PublicKeyToken=null" /> </ databaseTypes > < instances > < instance name ="EnterpriseLibrary" type ="Sqlserver" connectionString ="Sql Connection String" /> </ instances > < connectionStrings > < connectionString name ="Sql Connection String" > < parameters > < parameter name ="database" value ="EnterpriseLibrary" isSensitive ="false" /> < parameter name ="Integrated Security" value ="True" isSensitive ="false" /> < parameter name ="pwd" value ="" isSensitive ="true" /> < parameter name ="server" value ="shy" isSensitive ="false" /> < parameter name ="uid" value ="sa" isSensitive ="false" /> </ parameters > </ connectionString > </ connectionStrings > </ enterpriseLibrary.databaseSettings > </ xmlSerializerSection > </ dataConfiguration >

在Web.config文件中加入了下面内容:

< configSections > < section name ="enterpriselibrary.configurationSettings" type ="System.Configuration.IgnoreSectionHandler, System, Version=1.0.5000.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" /> </ configSections > < enterpriselibrary .configurationSettings xmlns:xsd ="http://www.w3.org/2001/XMLSchema" xmlns:xsi ="http://www.w3.org/2001/XMLSchema-instance" applicationName ="Application" xmlns ="http://www.microsoft.com/practices/enterpriselibrary/08-31-2004/configuration" > < configurationSections > < configurationSection xsi:type ="ReadOnlyConfigurationSectionData" name ="dataConfiguration" encrypt ="false" > < storageProvider xsi:type ="XmlFileStorageProviderData" name ="XML File Storage Provider" path ="dataConfiguration.config" /> < dataTransformer xsi:type ="XmlSerializerTransformerData" name ="Xml Serializer Transformer" > < includeTypes /> </ dataTransformer > </ configurationSection > </ configurationSections > < keyAlgorithmStorageProvider xsi:nil ="true" /> < includeTypes /> </ enterpriselibrary.configurationSettings >

到此为止,我们使用Data Access Application Block 的配置文件就基本上配置好了,下面我们来看看DataAccess Application Block 的几种基本操作:首先我们建立名为EnterpriseLibrary的数据库(这个应该在配置之前先建好的),在此数据库中建一张表,名为 Person .需要引用的程序集如下:Microsoft.Practices.EnterpriseLibrary.DataMicrosoft.Practices.EnterpriseLibrary.Configuration1.ExecuteNonQuery

/// <summary> /// 执行ExecuteNonQuery /// </summary> public void AddPerson() { Database db = DatabaseFactory.CreateDatabase("EnterpriseLibrary"); db.ExecuteNonQuery(CommandType.Text,"insert into person values(1,'pw',23,'男','3304122')"); }

2.ExecuteReader

/// <summary> /// 执行ExecuteReader，返回Person列表 /// </summary> /// <returns></returns> public IDataReader GetPersonList() { Database db = DatabaseFactory.CreateDatabase("EnterpriseLibrary"); string sql = "select * from person"; DBCommandWrapper dw = db.GetSqlStringCommandWrapper(sql); return db.ExecuteReader(dw); }

3.ExecuteDataSet

/// <summary> /// 执行ExecuteDataSet，返回Person列表 /// </summary> /// <returns></returns> public DataSet GetPersonList() { Database db = DatabaseFactory.CreateDatabase("EnterpriseLibrary"); string sql = "select * from person"; DBCommandWrapper dw = db.GetSqlStringCommandWrapper(sql); return db.ExecuteDataSet(dw); }

4.ExecuteScalar

/// <summary> /// 执行ExecuteScalar,返回单一的值 /// </summary> /// <returns></returns> public int GetPersonNum() { Database db = DatabaseFactory.CreateDatabase("EnterpriseLibrary"); string sql = "select count(*) from person"; DBCommandWrapper dw = db.GetSqlStringCommandWrapper(sql); return (int)db.ExecuteScalar(dw); }

5.执行存储过程

// 执行存储过程 // 首先我们在数据库中建一个名为"SelectPersonBySex"的存储过程 // 如果有输入参数可以这样写：dw.AddOutParameter("@sex",System.Data.DbType.String,'男'); // 执行完存储过程后取输出参数的值的方法是：dw.GetParameterValue("@sex"); public DataSet GetPersonListBySex( string sex) { Database db = DatabaseFactory.CreateDatabase("EnterpriseLibrary"); DBCommandWrapper dw = db.GetStoredProcCommandWrapper("SelectPersonBySex"); dw.AddInParameter("@sex",System.Data.DbType.String,sex); return db.ExecuteDataSet(dw); }

6.在程序中加入事务

public void InsertPerson() { //创建数据库实例 Database db = DatabaseFactory.CreateDatabase("EnterpriseLibrary"); //在程序中加入事务 using (IDbConnection conn = db.GetConnection()) { //打开连接 conn.Open(); //建立一个事务 System.Data.IDbTransaction trans = conn.BeginTransaction(); try { //循环向person表插入记录 for(int i=2;i<10;i++) { db.ExecuteNonQuery(CommandType.Text,@"insert into person values(" + i + ",'pw1',23,'男','3304122')"); } //提交事务 trans.Commit(); } catch(Exception) { //回滚事务 trans.Rollback(); } finally { //关闭连接 conn.Close(); } } }

关于DataAccess Application Block 的基本操作就说到这,以后再有更深的研究我继续往上发,还有想了解一下,学过Enterprise Library的朋友们对它的看法,欢迎在此发表你的个人意见.

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