c__数据库连接和操作大全

1、c# 数据库连接和操作大全一：数据库连接代码：SqlConnection objSqlConnection = new SqlConnection ("server = ;uid = sa; pwd =;database =test");objSqlConnection.Open();二：数据库的添加记录代码：            int i = 0;       &

2、#160;  string s1 = "", s2 = ""          i = Convert.ToInt16(textBox1.Text);              s1 = textBox2.Text;       

3、   s2 = textBox3.Text;            SqlConnection objSqlConnection = new SqlConnection("server = ;uid = sa; pwd =;database =test");            objSq

4、lConnection.Open();                        MessageBox.Show("数据库连接成功", "好");              

5、try                                 SqlCommand sqlcom = new SqlCommand("insert into info(id,name,sex) values( " + i + ",'

6、" + s1 + "','" + s2 + "')", objSqlConnection);                  sqlcom.ExecuteNonQuery();              

7、     MessageBox.Show("添加成功！", "啊");                             catch (Exception a)      &

8、#160;                           MessageBox.Show(a.ToString();                    

9、;       MessageBox.Show("添加成功！", "啊");三：数据库的修改代码：            int i = 0;            string s1 = "", s2 = ""

10、;            s1 = textBox2.Text;            s2 = textBox3.Text;            if (textBox1.Text.Length = 0)  

11、0;             i = 0;            else                i = Convert.ToInt32(textBox1.Text); &

12、#160;          SqlConnection objSqlConnection = new SqlConnection("server = ;uid = sa; pwd =;database =test");            objSqlConnection.Open();    &

13、#160;       MessageBox.Show("数据库连接成功", "好");            try                     

14、       SqlCommand sqlcom = new SqlCommand("update info set name='"+s1+"',sex='"+s2+"'"+"where id=" + i, objSqlConnection);              

15、60; sqlcom.ExecuteNonQuery();                MessageBox.Show("修改成功！", "啊");                objSqlConnection.Close()

16、;                        catch (Exception a)                      

17、0;     MessageBox.Show(a.ToString();            四：数据库的删除代码：            int i = 0;            st

18、ring s1 = "", s2 = ""            s1 = textBox2.Text;            s2 = textBox3.Text;            if(te

19、xtBox1.Text.Length=0)                i=0;            else                 i = Co

20、nvert.ToInt16(textBox1.Text);            SqlConnection objSqlConnection = new SqlConnection("server = ;uid = sa; pwd =;database =test");              &

21、#160;         objSqlConnection.Open();            MessageBox.Show("数据库连接成功", "好");            try   

22、                         SqlCommand sqlcom = new SqlCommand("delete from info where id="+i, objSqlConnection);         &

23、#160;      sqlcom.ExecuteNonQuery();                MessageBox.Show("删除成功！", "啊");              

24、0; objSqlConnection.Close();                        catch (Exception a)                 &#

25、160;          MessageBox.Show(a.ToString();            五：数据库的查询代码：            1.类开始：       

26、0;          DataTable dt1 = new DataTable();                  SqlDataAdapter da1 = new SqlDataAdapter();         &#

27、160;  2.按钮代码：            int i = 0,n=0;            string s1 = "", s2 = ""            s1 =

28、 textBox2.Text;            s2 = textBox3.Text;           if (textBox1.Text.Length = 0)                i = 0;&#

29、160;           else                i = Convert.ToInt32(textBox1.Text);            SqlConnection objSqlCon

30、nection = new SqlConnection("server = ;uid = sa; pwd =;database =test");            objSqlConnection.Open();            MessageBox.Show("数据库连接成功", &quo

31、t;好");            string query = "SELECT * from info where id="+i;            DataSet objDataSet = new DataSet();        

32、0;   SqlDataAdapter obj = new SqlDataAdapter();                       obj.SelectCommand = new SqlCommand(query, objSqlConnection);       

33、60;    obj.Fill(objDataSet, "info");                     SqlCommand objSqlCommand = new SqlCommand(query, objSqlConnection);       

34、0;    SqlDataReader objSqlReader = objSqlCommand.ExecuteReader();             while (objSqlReader.Read()                   &#

35、160;                n += 1;                    MessageBox.Show("编号: " + objSqlReader.Getvalue(0) + " 

36、; 姓名:" + objSqlReader.Getvalue(1) + "  性别" + objSqlReader.Getvalue(2);                                if (n =

37、0)                    MessageBox.Show("数据库中没有这样的记录！");六：数据库的查询代码：       int i = 0;           / int n = 0; 

38、;           string s1 = "", s2 = ""            string sql;            s1 = textBox2.Text;  

39、0;         s2 = textBox3.Text;            if (textBox1.Text.Length = 0)                    

40、0;       i = 0;                                        else 

41、               i = Convert.ToInt32(textBox1.Text);           SqlConnection objSqlConnection = new SqlConnection("server = ;uid = sa; pwd =;database =test");

42、                      objSqlConnection.Open();            MessageBox.Show("数据库连接成功", "好");   &#

43、160;        string query = "SELECT * from info where id="+i;            if(i=0)                  sql

44、 = "select * from info "            else                  sql = "select * from info where id=" + i;     &

45、#160;      da1 = new SqlDataAdapter(sql, objSqlConnection);            dt1.Clear();            da1.Fill(dt1);       

46、;     dataGridView1.DataSource = dt1;数据库的封装类代码：class DBClass            public void dbclass(string  sql)                 

47、;   try                            SqlConnection sqlcon = new SqlConnection("server = ;uid = sa; pwd =;database =test"); 

48、               sqlcon.Open();                             SqlTransaction objt = sqlco

49、n.BeginTransaction();  /事物开始                              SqlCommand sqlcom = new SqlCommand(sql, sqlcon);     

50、0;                          sqlcom.Transaction = objt; /将Command 对象设置为事物处理的对象               

51、60;            sqlcom.ExecuteNonQuery();                objt.Commit();         /提交事物                sqlcon.Close();