前端界面操作数据库

前端界面操作数据库

一、思维导图

 

二、知识点介绍

前端操作数据要用到的不仅仅是浮现在用户前面的一堆控件，控件的背后还需要代码的支持才能真正的做到，运用前端操作数据库。

首先，我们要连接数据库：

                  InitializeComponent(); SqlConnection sqlConnection = new SqlConnection();

                    sqlConnection.ConnectionString =

                          "Server=(Local);Database=EMR;Integrated Security=sspi";

                  sqlConnection.Open();

                  MessageBox.Show

                          ("连接状态：" + sqlConnection.State.ToString()

                          + " 工作站标识：" + sqlConnection.WorkstationId

                          + " 服务器地址：" + sqlConnection.DataSource

                          + " 服务器版本：" + sqlConnection.ServerVersion

                          + " 数据库名称：" + sqlConnection.Database

                          + " （单击【确定】后将关闭SQL连接）");

                  sqlConnection.Close();

                  MessageBox.Show

                          ("连接状态：" + sqlConnection.State.ToString());

         接着，我们进行注册：

            SqlConnection sqlConnection = new SqlConnection();

            sqlConnection.ConnectionString =

                ConfigurationManager.ConnectionStrings["ConnString"].ConnectionString;

            SqlCommand sqlCommand = new SqlCommand();

 

            sqlCommand.Connection = sqlConnection;

            sqlCommand.CommandText ="INSERT 学生 (学号，姓名,班级，电话)

 

            VALUES(@学号，@姓名,@班级，@电话);";

            sqlCommand.Parameters.AddWithValue("@学号", cob_学号 .Text.Trim());

            sqlCommand.Parameters.AddWithValue("@姓名", cob_姓名 .Text.Trim());

sqlCommand.Parameters.AddWithValue("@班级", cob_班级 .Text.Trim());

sqlCommand.Parameters.AddWithValue("@电话", cob_电话 .Text.Trim());

 

 

            sqlConnection.Open();

            int rowAffected = sqlCommand.ExecuteNonQuery();

            sqlConnection.Close();

            MessageBox.Show("保存成功");

然后，我们来试验一下是否可以登录：

 

         SqlConnection sqlConnection = new SqlConnection();

         sqlConnection.ConnectionString =

                  ConfigurationManager.ConnectionStrings["Sql"].ConnectionString;

         SqlCommand sqlCommand = new SqlCommand();                                                 

         sqlCommand.Connection = sqlConnection;                                                               if (button1_Click_1.Checked == true)

         {

                  sqlCommand.CommandText =

                          "SELECT * FROM EMR WHERE XH=@XH AND Name=@Name;

                  sqlParameter.ParameterName= "@XH";

                  sqlParameter.Value = this.textBox1.Text.Trim();

                  sqlParameter.SqlDbType = SqlDbType.VarChar;

                  sqlParameter.Size = 20;

                  sqlCommand.Parameters.Add(sqlParameter);

                  sqlCommand.Parameters.AddWithValue("@Name", this.textbxpsw.Text.Trim());

                  sqlCommand.Parameters["@Name"].SqlDbType = SqlDbType.VarChar;

　　　　　MessageBox.Show("登陆成功","登陆成功");

         }