本文实例为大家分享了C#实现学生模块的增删改查的具体代码，供大家参考，具体内容如下
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using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Data.SqlClient;using System.Drawing;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace text3_CRUD{ public partial class Form1 : Form { //把连接数据库的字符串提取出来，就不用每次都要写，增加代码复用性 private string str = "data source=本地IP;initial catalog=数据库名;user ID=用户名;pwd=密码"; public Form1() { InitializeComponent(); } private void TextBox5_TextChanged(object sender, EventArgs e) { } private void Form1_Load(object sender, EventArgs e) { } private void Label10_Click(object sender, EventArgs e) { } /// <summary> /// 添加学生信息档案 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void ButAdd_Click(object sender, EventArgs e) { //获取各个文本框的数据 string name = txtname.Text; string sex = txtsex.Text; string college = txtcollege.Text; string id = txtid.Text; string grade = txtgrade.Text; string phone = txtphone.Text; string email = txtemail.Text; string qq = txtqq.Text; string room = txtroom.Text; using (var conn = new SqlConnection(this.str))//定义一个数据库连接实例 { conn.Open();//打开数据库 Form1 f = new Form1();//实例化Form1窗体对象 if (f.Existence(id, conn))//检查数据库 存不存在此条记录，存在则插入 { SqlParameter[] para = new SqlParameter[]//构建存储过程的输入参数 { new SqlParameter("@name",name), new SqlParameter("@sex", sex), new SqlParameter("@college", college), new SqlParameter("@id", id), new SqlParameter("@grade", grade), new SqlParameter("@phone", phone), new SqlParameter("@email", email), new SqlParameter("@qq", qq), new SqlParameter("@room", room), }; string sql = "insert into Students values(@name, @sex, @college, @id, @grade, @phone, @email, @qq, @room);";//定义一个数据库操作指令集 SqlCommand com = new SqlCommand(sql, conn);//执行数据库操作指令 com.Parameters.AddRange(para);//將参数和命令对象的参数集合绑定 int result = (int)com.ExecuteNonQuery();//针对Connection执行的SQL语句，返回受影响的行数，result > 0则表示SQL语句执行成功 if (result > 0) { MessageBox.Show("添加成功！");//弹窗显示“添加成功” this.Form1_Load_1(null, null);//刷新数据 } else { MessageBox.Show("添加失败！"); } } else { MessageBox.Show("数据已经存在！"); } conn.Close();//关闭数据库 //Application.Exit();//关闭整个应用程序 } } /// <summary> /// 根据ID值判断数据表Students中是否存在这个人，存在返回false，不存在返回true /// </summary> /// <param name="id"></param> /// <param name="conn"></param> /// <returns></returns> public bool Existence(string id, SqlConnection conn) { string txtStr = string.Format( "select id from Students where id = '{0}' " ,id);//定义一个数据库操作指令集 SqlDataAdapter sda = new SqlDataAdapter(txtStr, conn);//定义一个数据库适配器 DataSet ds = new DataSet();//定义数据集合 sda.Fill(ds);//填充数据集合 DataTable dt = ds.Tables[0];//將数据集合中的第一张表赋值给DataTable if(dt.Rows.Count > 0) //count > 0表示有数据 { return false; } else { return true; } } /// <summary> /// 对数据库进行的动态查询，不管用户掌握的信息有多少都可以查询 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void BtnSelect_Click(object sender, EventArgs e) { //获取各个文本框的数据 string name = txtname.Text; string sex = txtsex.Text; string college = txtcollege.Text; string id = txtid.Text; string grade = txtgrade.Text; string phone = txtphone.Text; string email = txtemail.Text; string qq = txtqq.Text; string room = txtroom.Text; using(var conn = new SqlConnection(this.str))//定义一个数据库连接实例 { conn.Open();//打开数据库 StringBuilder sb = new StringBuilder();//创建一个字符串变量 sb.Append("select name, sex, college, id, grade,phone, email, qq, room from Students where 1=1"); //判断用户有没有给出其它的查询条件，有则添加进sql语句 if (name != "") { sb.AppendFormat(" and name = '{0}'", name); } if (sex != "") { sb.AppendFormat(" and sex = '{0}'", sex); } if (college != "") { sb.AppendFormat(" and college = '{0}'", college); } if (id != "") { sb.AppendFormat(" and id = '{0}'", id); } if (grade != "") { sb.AppendFormat(" and grade = '{0}'", grade); } if (phone != "") { sb.AppendFormat(" and phone = '{0}'", phone); } if (email != "") { sb.AppendFormat(" and email = '{0}'", email); } if (qq != "") { sb.AppendFormat(" and qq = '{0}'", qq); } if (room != "") { sb.AppendFormat(" and room = '{0}'", room); } string sql = sb.ToString(); SqlDataAdapter adapter = new SqlDataAdapter(sql, conn); DataSet ds = new DataSet();//定义一个数据集合 adapter.Fill(ds);//填充数据集合 dataGridView1.DataSource = ds.Tables[0];//把数据集合绑定到dataGridView上，dataGridView会以表格的形式显示出来 conn.Close();//关闭数据库 } } /// <summary> /// 修改学生信息 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void BtnUpdate_Click(object sender, EventArgs e) { //获取各个文本框的数据 string name = txtname.Text; string sex = txtsex.Text; string college = txtcollege.Text; string id = txtid.Text; string grade = txtgrade.Text; string phone = txtphone.Text; string email = txtemail.Text; string qq = txtqq.Text; string room = txtroom.Text; //构建存储过程的输入参数 SqlParameter[] para = new SqlParameter[] { new SqlParameter("@name",name), new SqlParameter("@sex", sex), new SqlParameter("@college", college), new SqlParameter("@id", id), new SqlParameter("@grade", grade), new SqlParameter("@phone", phone), new SqlParameter("@email", email), new SqlParameter("@qq", qq), new SqlParameter("@room", room) }; using(var conn = new SqlConnection(this.str)) { conn.Open();//打开数据库； string sql = "update Students set name = @name, sex = @sex, college = @college, id = @id, grade = @grade, phone = @phone, email = @email, qq = @qq, room = @room where id = @id"; SqlCommand com = new SqlCommand(sql, conn);//执行数据库操作指令 com.Parameters.AddRange(para);//将参数和命令对象的参数集合绑定 int result = (int)com.ExecuteNonQuery();//查询返回的第一行第一列 if(result > 0) { MessageBox.Show("修改成功！"); this.Form1_Load_1(null, null);//修改完数据后，重新刷新属性Form1窗口，以查看变化的内容 conn.Close();//关闭数据库 } } //SqlDataAdapter sda = new SqlDataAdapter(); } /// <summary> /// 刷新DataGridView里的数据 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void Form1_Load_1(object sender, EventArgs e) { using (var conn = new SqlConnection(this.str))//定义一个数据库连接实例 { conn.Open();//打开数据库 string sql = "select * from Students";//定义一个数据库操作指令 SqlDataAdapter sda = new SqlDataAdapter(sql, conn);//定义数据库适配器 DataSet ds = new DataSet();//定义数据集合 sda.Fill(ds);//填充数据集合 dataGridView1.DataSource = ds.Tables[0]; conn.Close();//关闭数据库 } } private void DataGridView1_CellClick(object sender, DataGridViewCellEventArgs e) { } /// <summary> /// 选中DataGridView的行，这一行的数据返回到对应的文本框 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void DataGridView1_CellClick_1(object sender, DataGridViewCellEventArgs e) { //SelectedRows[0] 获取用户选定行的集合(选中的第一行就是0，一次类推) //Cells["name"] 获取用于填充行的单元格集合(就是列) .Value就是它的值,最后ToString转字符串 txtname.Text = dataGridView1.SelectedRows[0].Cells["name"].Value.ToString(); txtsex.Text = dataGridView1.SelectedRows[0].Cells["sex"].Value.ToString(); txtcollege.Text = dataGridView1.SelectedRows[0].Cells["college"].Value.ToString(); txtid.Text = dataGridView1.SelectedRows[0].Cells["id"].Value.ToString(); txtgrade.Text = dataGridView1.SelectedRows[0].Cells["grade"].Value.ToString(); txtphone.Text = dataGridView1.SelectedRows[0].Cells["phone"].Value.ToString(); txtemail.Text = dataGridView1.SelectedRows[0].Cells["email"].Value.ToString(); txtqq.Text = dataGridView1.SelectedRows[0].Cells["qq"].Value.ToString(); txtroom.Text = dataGridView1.SelectedRows[0].Cells["room"].Value.ToString(); } /// <summary> /// 删除某个学生的所有数据 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void BtnDelete_Click(object sender, EventArgs e) { using(var conn = new SqlConnection(this.str))//创建一个数据库连接实例 { conn.Open();//连接数据库 string sql = string.Format("delete from Students where id = '{0}'", txtid.Text);//往数据库操作指令中传值 //如果传的值不是很多的话，就用这种方法；如果有很多就用SqlParameter[] SqlCommand com = new SqlCommand(sql, conn);//执行数据库删除指令 int result = (int)com.ExecuteNonQuery();//返回结果，result > 0则为修改成功 if(result > 0) { MessageBox.Show("删除成功！"); this.Form1_Load_1(null, null);//刷新数据 conn.Close();//关闭数据库 } } } /// <summary> /// 对文本框进行清空处理，方便重新输入下一个学生信息 /// </summary> /// <param name="sender"></param> /// <param name="e"></param> private void BtnClear_Click(object sender, EventArgs e) { txtname.Text = null; txtsex.Text = null; txtcollege.Text = null; txtid.Text = null; txtgrade.Text = null; txtphone.Text = null; txtemail.Text = null; txtqq.Text = null; txtroom.Text = null; } }} |
Students表
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/kuguhuan/article/details/98478924
