C#數據庫查詢和操作大全
作者：佚名
這里將介紹C#數據庫查詢和操作方面的有關知識，包括數據庫連接、數據庫查詢的相關代碼和示例。希望本文對大家有所幫助。
一：C#數據庫查詢之數據庫連接代碼：
- SqlConnectionobjSqlConnection=newSqlConnection("server=127.0.0.1;uid=sa;pwd=;database=test");
- objSqlConnection.Open();
二：數據庫的添加記錄代碼：
- inti=0;
- strings1="",s2="";
- i=Convert.ToInt16(textBox1.Text);
- s1=textBox2.Text;
- s2=textBox3.Text;
- SqlConnectionobjSqlConnection=newSqlConnection("server=127.0.0.1;uid=sa;pwd=;database=test");
- objSqlConnection.Open();
- MessageBox.Show("數據庫連接成功","好");
- try
- {
- SqlCommandsqlcom=newSqlCommand("insertintoinfo(id,name,sex)values("+i+",'"+s1+"','"+s2+"')",objSqlConnection);
- sqlcom.ExecuteNonQuery();
- MessageBox.Show("添加成功！","啊");
- }
- catch(Exceptiona)
- {
- MessageBox.Show(a.ToString());
- }
- MessageBox.Show("添加成功！","啊");
- }
三：數據庫的修改代碼：
- inti=0;
- strings1="",s2="";
- s1=textBox2.Text;
- s2=textBox3.Text;
- if(textBox1.Text.Length==0)
- i=0;
- else
- i=Convert.ToInt32(textBox1.Text);
- SqlConnectionobjSqlConnection=newSqlConnection("server=127.0.0.1;uid=sa;pwd=;database=test");
- objSqlConnection.Open();
- MessageBox.Show("數據庫連接成功","好");
- try
- {
- SqlCommandsqlcom=newSqlCommand("updateinfosetname='"+s1+"',sex='"+s2+"'"+"whereid="+i,objSqlConnection);
- sqlcom.ExecuteNonQuery();
- MessageBox.Show("修改成功！","啊");
- objSqlConnection.Close();
- }
- catch(Exceptiona)
- {
- MessageBox.Show(a.ToString());
- }
四：數據庫的刪除代碼：
- inti=0;
- strings1="",s2="";
- s1=textBox2.Text;
- s2=textBox3.Text;
- if(textBox1.Text.Length==0)
- i=0;
- else
- i=Convert.ToInt16(textBox1.Text);
- SqlConnectionobjSqlConnection=newSqlConnection("server=127.0.0.1;uid=sa;pwd=;database=test");
- objSqlConnection.Open();
- MessageBox.Show("數據庫連接成功","好");
- try
- {
- SqlCommandsqlcom=newSqlCommand("deletefrominfowhereid="+i,objSqlConnection);
- sqlcom.ExecuteNonQuery();
- MessageBox.Show("刪除成功！","啊");
- objSqlConnection.Close();
- }
- catch(Exceptiona)
- {
- MessageBox.Show(a.ToString());
- }
五：數據庫的查詢代碼：
1.類開始：
- DataTabledt1=newDataTable();
- SqlDataAdapterda1=newSqlDataAdapter();
2.按鈕代碼：
- inti=0,n=0;
- strings1="",s2="";
- s1=textBox2.Text;
- s2=textBox3.Text;
- if(textBox1.Text.Length==0)
- i=0;
- else
- i=Convert.ToInt32(textBox1.Text);
- SqlConnectionobjSqlConnection=newSqlConnection("server=127.0.0.1;uid=sa;pwd=;database=test");
- objSqlConnection.Open();
- MessageBox.Show("數據庫連接成功","好");
- stringquery="SELECT*frominfowhereid="+i;
- DataSetobjDataSet=newDataSet();
- SqlDataAdapterobj=newSqlDataAdapter();
- obj.SelectCommand=newSqlCommand(query,objSqlConnection);
- obj.Fill(objDataSet,"info");
- SqlCommandobjSqlCommand=newSqlCommand(query,objSqlConnection);
- SqlDataReaderobjSqlReader=objSqlCommand.ExecuteReader();
- while(objSqlReader.Read())
- {
- n+=1;
- MessageBox.Show("編號:"+objSqlReader.Getvalue(0)+"姓名:"+objSqlReader.Getvalue(1)+"性別"+objSqlReader.Getvalue(2));
- }
- if(n==0)
- MessageBox.Show("數據庫中沒有這樣的記錄！");
六：C#數據庫查詢代碼：
- inti=0;
- //intn=0;
- strings1="",s2="";
- stringsql;
- s1=textBox2.Text;
- s2=textBox3.Text;
- if(textBox1.Text.Length==0)
- {
- i=0;
- }
- else
- i=Convert.ToInt32(textBox1.Text);
- SqlConnectionobjSqlConnection=newSqlConnection("server=127.0.0.1;uid=sa;pwd=;database=test");
- objSqlConnection.Open();
- MessageBox.Show("數據庫連接成功","好");
- stringquery="SELECT*frominfowhereid="+i;
- if(i==0)
- sql="select*frominfo";
- else
- sql="select*frominfowhereid="+i;
- da1=newSqlDataAdapter(sql,objSqlConnection);
- dt1.Clear();
- da1.Fill(dt1);
- dataGridView1.DataSource=dt1;
C#數據庫查詢之數據庫的封裝類代碼：
- classDBClass
- {
- publicvoiddbclass(stringsql)
- {
- try
- {
- SqlConnectionsqlcon=newSqlConnection("server=127.0.0.1;uid=sa;pwd=;database=test");
- sqlcon.Open();
- SqlTransactionobjt=sqlcon.BeginTransaction();//事物開始
- SqlCommandsqlcom=newSqlCommand(sql,sqlcon);
- sqlcom.Transaction=objt;//將Command對象設置為事物處理的對象
- sqlcom.ExecuteNonQuery();
- objt.Commit();//提交事物
- sqlcon.Close();
- }
- catch(Exceptiona)
- {
- MessageBox.Show(a.ToString());
- }
- }
- }
- --db2數據庫連接代碼：
- stringstrcon="Provider=IBMDADB2;DataSource=hfzd;UserId=db2admin;Password=db2admin";
- //stringsql="select*fromADMINISTRATOR.HFZD";
- stringsql="deletefromADMINISTRATOR.HFZDwhereID=1";
- OleDbConnectionolecon=newOleDbConnection(strcon);
- olecon.Open();
- MessageBox.Show("數據庫已連接上");
- dt.Clear();
- da=newOleDbDataAdapter(sql,olecon);
- da.Fill(dt);
- dataGridView1.DataSource=dt;
- olecon.Close();
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責任編輯：彭凡
來源：
bbs.gameres.com
