c#学习笔记－数据库操作

在Dataset和datagridview中对数据进行删除、取消等操作，并将结果保存到数据库中。

Form1.cs

usingSystem;

usingSystem.Collections.Generic;51Testing软件测试网
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usingSystem.ComponentModel;

usingSystem.Data;

usingSystem.Drawing;

usingSystem.Text;51Testing软件测试网6IM3N,S,t(gflE

usingSystem.Windows.Forms;51Testing软件测试网6h:@.nd-i;l

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namespaceWindowsApplication2

{

   publicpartialclassForm1:Form51Testing软件测试网.x S'L fy(D0lg

   {

       publicForm1()

       {

           InitializeComponent();51Testing软件测试网L2E g.I%g6xx

           ClassLibrary1.oracledataaccess =newClassLibrary1.oracle();

           DataSetds = dataaccess.getData();51Testing软件测试网KUDT*Q1i/E}"jZg-}

          dataGridView1.DataSource = ds.Tables[0];

           /*首先我们通过form1里头的load事件把数据加载到了datagridview中,dataset(数据在内存51Testing软件测试网/gRQv\b/N

         中的缓存)已经和datagridview的datasource榜定在一起了*/

       }

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       privatevoidbutdelete_Click(objectsender,EventArgse)51Testing软件测试网_.|J$w5Z O

       {51Testing软件测试网|-mLxY3_Z*l

           if(this.dataGridView1.SelectedRows.Count > 0)

           {51Testing软件测试网[R/I@
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               for(inti =this.dataGridView1.SelectedRows.Count - 1; i >= 0; --i)

               {51Testing软件测试网X7~)_T2Tp*o]&u

                 DataRowViewrowview = ((DataRowView)this.dataGridView1.SelectedRows[i].DataBoundItem);

                   //获取用于填充行的数据绑带对象

                   rowview.Delete();

                   /*选中的行删除，但此时的被删除的数据并没有被真正的从数据库中删除，它只是51Testing软件测试网a
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                   做了一个删除标记。*/

                   System.Windows.Forms.MessageBox.Show(rowview.Row.RowState.ToString());

                  /*打出行的状态查看一下。Rowstate在此非常重要，因为将涉及到对数据库的操作51Testing软件测试网/{9p!ff8c$a

                  系统怎么判断这一批的数据是被删除掉了51Testing软件测试网|&?_$w'b0g(}w

               }51Testing软件测试网8f*p!Ct-]PfV

                 /*对于for循环中初始i值说明：datagridview将数据显示出来,每删除一行，51Testing软件测试网G5p p5FnH

               this.dataGridView1.SelectedRows.Count就会减少一行，因此初值要注意*/51Testing软件测试网5N,H
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           }51Testing软件测试网;d e!YM6a+L_5w\

       }51Testing软件测试网"F"q5?2c
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       privatevoidbutcancel_Click(objectsender,EventArgse)

       {51Testing软件测试网| r^hj!f#n5}

         ((DataTable)dataGridView1.DataSource).RejectChanges();51Testing软件测试网ldr(u.C+oi}

          //回滚上次更新该表的操作

       }

privatevoidbtnSave_Click(objectsender,EventArgse)

       {51Testing软件测试网8ed%AYz!YS"T

ClassLibrary1.oracledataaccess =newClassLibrary1.oracle();51Testing软件测试网:C"~j.Et

         dataaccess.deleteData(((DataTable)dataGridView1.DataSource).DataSet);

       }

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   }

}51Testing软件测试网 jo;Isc Idb

Oracle.cs51Testing软件测试网X ^@d | X5[Yn

usingSystem;

usingSystem.Collections.Generic;

usingSystem.Text;51Testing软件测试网4AF0^p [-xc

usingSystem.Data .OracleClient;51Testing软件测试网g
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usingSystem.Data;51Testing软件测试网`H ur6RSYIr

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namespaceClassLibrary151Testing软件测试网?3t K f8u"\

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   public classoracle51Testing软件测试网g/UK+K g6]'Ru9J9t rw

   {

       stringmyConnectionText ="Data Source=MYORACLE;User Id=SYSTEM;Password=SYSTEM";

       stringmySelectText ="SELECT * from scott.student";

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       publicDataSetgetData()51Testing软件测试网,S!tp
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       {51Testing软件测试网6S0Z1x1ufb

           OracleDataAdaptercustDA =newOracleDataAdapter(mySelectText, myConnectionText);

　　　　　//实例化一个适配器,创建数据库的连接

           OracleConnectioncustConn = custDA.SelectCommand.Connection;51Testing软件测试网Oe!L%M5_*nI^

           //打开数据库的连接51Testing软件测试网 G\^ue#EA

            DataSetds =newDataSet();

           custDA.Fill(ds);

           //将对数据库的查询结果添加到DateSet中。51Testing软件测试网
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           returnds;

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       }51Testing软件测试网DDN1F7M*F

   }51Testing软件测试网Uo%KW&o

}51Testing软件测试网.aW;PdySUHK

最后的图片51Testing软件测试网9hr8G kIp

 删除选中行以后

在form1.cs设计中，拖拉一个datagridview，添加三个按钮，分别将它们的name和text属性改为51Testing软件测试网 Zm.A6T'f7X

butdelete.Name ="butdelete";51Testing软件测试网 U#I1eJ+wAp2`

butdelete.Text ="删除选中";

butcancel.Name ="butcancel";

butcancel.Text ="取消删除";

butsave.Name ="butsave";

butsave.Text ="保存";51Testing软件测试网@-W:M!\)_$l*f