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。51Testing软件测试网 U9BK%_)J``&L

Form1.cs

usingSystem;51Testing软件测试网l.X i$F^

usingSystem.Collections.Generic;

usingSystem.ComponentModel;

usingSystem.Data;51Testing软件测试网l
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usingSystem.Drawing;51Testing软件测试网?S"KP] |

usingSystem.Text;

usingSystem.Windows.Forms;51Testing软件测试网 TwK+W!Z]r&F5U

namespaceWindowsApplication2

{

   publicpartialclassForm1:Form

   {

       publicForm1()

       {

           InitializeComponent();

           ClassLibrary1.oracledataaccess =newClassLibrary1.oracle();

           DataSetds = dataaccess.getData();

          dataGridView1.DataSource = ds.Tables[0];51Testing软件测试网:pq9G\(Q1~-Y

           /*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U:o5Y9l2?

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

       }51Testing软件测试网4Mn3Yz}{#j#FN

       privatevoidbutdelete_Click(objectsender,EventArgse)51Testing软件测试网/X7t}1zv"u[

       {51Testing软件测试网
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           if(this.dataGridView1.SelectedRows.Count > 0)

           {

               for(inti =this.dataGridView1.SelectedRows.Count - 1; i >= 0; --i)

               {51Testing软件测试网&b4nv1c-Juu i

                 DataRowViewrowview = ((DataRowView)this.dataGridView1.SelectedRows[i].DataBoundItem);51Testing软件测试网,H @%qV4u:OH0?

                   //获取用于填充行的数据绑带对象51Testing软件测试网Mim
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                   rowview.Delete();51Testing软件测试网jnO#N;[:`6e3U

                   /*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

                   做了一个删除标记。*/

                   System.Windows.Forms.MessageBox.Show(rowview.Row.RowState.ToString());51Testing软件测试网:Ym'k9p9{U

                  /*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

                  系统怎么判断这一批的数据是被删除掉了51Testing软件测试网 sG]T8L5B

               }51Testing软件测试网J;X'|%h!b'R0]Y4t5F

                 /*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，

               this.dataGridView1.SelectedRows.Count就会减少一行，因此初值要注意*/

           }51Testing软件测试网5DV^r F3i.Q

       }

       privatevoidbutcancel_Click(objectsender,EventArgse)51Testing软件测试网n*J&k,dm(JO ]v#e!n@

       {

         ((DataTable)dataGridView1.DataSource).RejectChanges();

          //回滚上次更新该表的操作

       }

privatevoidbtnSave_Click(objectsender,EventArgse)51Testing软件测试网HjIn(jo/`

       {

ClassLibrary1.oracledataaccess =newClassLibrary1.oracle();51Testing软件测试网1e
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         dataaccess.deleteData(((DataTable)dataGridView1.DataSource).DataSet);51Testing软件测试网m-F%m|8]y1o,}2c

       }51Testing软件测试网 X D/^Z*[

   }

}

Oracle.cs51Testing软件测试网;m(tky(N.lBr5n)^

usingSystem;51Testing软件测试网sIZ:jQ&I[h8Y

usingSystem.Collections.Generic;

usingSystem.Text;51Testing软件测试网5w
Ys-d;gk

usingSystem.Data .OracleClient;

usingSystem.Data;

 51Testing软件测试网4Z'B-`"`]f!{*u]

namespaceClassLibrary151Testing软件测试网rS~7fg%E`.m

{51Testing软件测试网w%nK/cq)]/h:v

   public classoracle

   {

       stringmyConnectionText ="Data Source=MYORACLE;User Id=SYSTEM;Password=SYSTEM";51Testing软件测试网F!N iE0Zk

       stringmySelectText ="SELECT * from scott.student";51Testing软件测试网-v#W)Y4c;V

 51Testing软件测试网%b%ud%D P_ G'A|

       publicDataSetgetData()51Testing软件测试网p;p*h&MC+L
I-T

       {

           OracleDataAdaptercustDA =newOracleDataAdapter(mySelectText, myConnectionText);51Testing软件测试网 xwE$NY.\8Zw

　　　　　//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(_:\M$j1k

           //打开数据库的连接

            DataSetds =newDataSet();51Testing软件测试网/I6W'lZFZ-|\

           custDA.Fill(ds);51Testing软件测试网b b,K-ub"SWk

           //将对数据库的查询结果添加到DateSet中。51Testing软件测试网NM
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           returnds;51Testing软件测试网t+_A,y7t

 51Testing软件测试网6Y MSXb\;r

       }51Testing软件测试网YkF/YQGthQ#B

   }51Testing软件测试网D!z7A9N2\~+M5M.R

}

最后的图片51Testing软件测试网5g;iG n*h

51Testing软件测试网!vE&m;?S9J

 删除选中行以后51Testing软件测试网lZ6bG~*b

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[&L^3ZU/t1@,?

butdelete.Name ="butdelete";51Testing软件测试网mX,M.v$F2w

butdelete.Text ="删除选中";51Testing软件测试网*A6i,Z^o2Cl6xS~|]

butcancel.Name ="butcancel";51Testing软件测试网Yw1~&oM

butcancel.Text ="取消删除";51Testing软件测试网*v'~?)Y gyJ

butsave.Name ="butsave";

butsave.Text ="保存";51Testing软件测试网&r;Qp(n%gd[