C#连接Sql Serve数据库及增，删，改操作

一：连接。

string sqlconn = "server=主机名;database=数据名;integrated security=true"
//integrated security 当为true时，将使用当前的Windows帐户凭据进行身份验证。    
string sqlconn = "server=主机名;database=数据名;uid=用户ID;pwd=密码;"
//integrated security 当为false时，将在连接中指定用户ID和密码。
string sqlcomm = "select * from student_info";//sql语句
SqlConnection conn = new SqlConnection(sqlconn);
conn.Open();
SqlCommand comm = new SqlCommand(sqlcom, conn);

 二：通过TextBox控件添加。

string sno = snoTextBox.Text;
string name = nameTextBox.Text;
string sex = sexTextBox.Text;
nt age = Convert.ToInt32(ageTextBox.Text);
string sqlconn = "server=.;database=student;integrated security=true";
string sqlcomm = "insert into student_info values('"+sno+"','"+name+"',"+age+",'"+sex+"')";
SqlConnection conn = new SqlConnection(sqlconn);
conn.Open();
SqlCommand comm = new SqlCommand(sqlcomm, conn);
comm.ExecuteNonQuery();
conn.Close();

三：删除。

string sno = snoTextBox.Text;
string sqlconn = "server=.;database=student;integrated security=true";
string sqlcomm = "delete from student_info where stu_sno=" + sno;
SqlConnection conn = new SqlConnection(sqlconn);
conn.Open();
SqlCommand comm = new SqlCommand(sqlcomm, conn);
comm.ExecuteNonQuery();
conn.Open();

三：更新。

string sno = snoTextBox.Text;
string name = nameTextBox.Text;
string sex = sexTextBox.Text;
int age = Convert.ToInt32(ageTextBox.Text);
string sqlconn = "server=.;database=student;integrated security=true";
string sqlcomm = "update student_info set stu_sno='"+sno+"',stu_name='"+name+"',stu_sex='"+sex+"',stu_age="+age+" where stu_sno=" + sno; 
SqlConnection conn = new SqlConnection(sqlconn);
conn.Open();
SqlCommand comm = new SqlCommand(sqlcomm, conn);
comm.ExecuteNonQuery();
conn.Close();

上面的代码是全部数据一块更新的，也可以只更新某些数据项。