VS&C#&数据库大作业-学生信息管理系统

本文共34866 字（代码占比较大），预计阅读时长10mis左右
代码下载 视频链接 见最后

指导老师： HBU_David
开发工具： Microsoft Visual Studio & Microsoft SQL Server
语言： C# & SQL
功能介绍：
—— 主窗口是登录界面，此外可大致分为3个模块：注册账号，忘记密码，选择身份进行登录。管理员可执行4个操作：查看登陆日志；学生信息管理；课程管理；成绩管理。用户两个窗口可执行3个操作：查询成绩&添加课程；查看开设课程。

VS中控件：
无操作文字：Lable
输入框：textBox
按钮：Button
数据表格：dataGridView
组合框：comboBox
日期选择：dateTimePicker
窗体背景：点击窗体边缘 更改属性->BackgroundImage

更改图标样式：（事先准备图标）

SQL建表准备

进行操作之前需要把每张表准备好，其实不必要一下子全想出来，做着做着就知道自己需要哪张了哈哈哈！
这里三张基本表无需多说，其余
Managetable： 用来存储管理员的信息（为了登录，修改密码…使用）
Usertable： 用来存储用户的信息（为了登录，修改密码…使用）
SchLog： 用来存放登录日志

建表代码

三张基本表（Student，Course，SC）的建表代码
这是老师写的三张基本表的建表代码 我的是在上面的基础上又加了点 因为“年少无知”忘记保存了…

--Edit by HBU_David @ HeBei University 2020.3.6

DROP TABLE IF EXISTS SC
DROP TABLE IF EXISTS Student
DROP TABLE IF EXISTS Course
 
CREATE TABLE Student          
 (	
 Sno CHAR(9) PRIMARY KEY,        /* 列级完整性约束条件,Sno是主码*/                  
 Sname CHAR(20) UNIQUE,          /* Sname取唯一值*/
 Ssex CHAR(2),
 Sage SMALLINT,
 Sdept CHAR(20)
 ); 
 
CREATE TABLE  Course
 (	
 Cno CHAR(4) PRIMARY KEY,
 Cname CHAR(40),            
 Cpno CHAR(4),               	                      
 Ccredit SMALLINT,
 FOREIGN KEY (Cpno) REFERENCES  Course(Cno) /* 表级完整性约束条件， Cpno是外码，被参照表是自身*/
 ); 
 
CREATE TABLE  SC
 (
 Sno CHAR(9), 
 Cno CHAR(4),  
 Grade SMALLINT,
 PRIMARY KEY (Sno,Cno),                      /* 主码由两个属性构成，必须作为表级完整性进行定义*/
 FOREIGN KEY (Sno) REFERENCES Student(Sno),  /* 表级完整性约束条件，Sno是外码，被参照表是Student*/
 FOREIGN KEY (Cno)REFERENCES Course(Cno)     /* 表级完整性约束条件，Cno是外码，被参照表是Course*/
 ); 
 
 
INSERT  INTO  Student (Sno,Sname,Ssex,Sdept,Sage) VALUES ('201215121','李勇','男','CS',20);
INSERT  INTO  Student (Sno,Sname,Ssex,Sdept,Sage) VALUES ('201215122','刘晨','女','CS',19);
INSERT  INTO  Student (Sno,Sname,Ssex,Sdept,Sage) VALUES ('201215123','王敏','女','MA',18);
INSERT  INTO  Student (Sno,Sname,Ssex,Sdept,Sage) VALUES ('201215125','张立','男','IS',19);
INSERT  INTO  Student (Sno,Sname,Ssex,Sdept,Sage) VALUES ('201215128','陈冬','男','IS',20);
 
SELECT * FROM Student
 
INSERT  INTO Course(Cno,Cname,Cpno,Ccredit)	VALUES ('1','数据库',NULL,4);
INSERT  INTO Course(Cno,Cname,Cpno,Ccredit)	VALUES ('2','数学',NULL,4);
INSERT  INTO Course(Cno,Cname,Cpno,Ccredit)	VALUES ('3','信息系统',NULL,4);
INSERT  INTO Course(Cno,Cname,Cpno,Ccredit)	VALUES ('4','操作系统',NULL,4);
INSERT  INTO Course(Cno,Cname,Cpno,Ccredit)	VALUES ('5','数据结构',NULL,4);
INSERT  INTO Course(Cno,Cname,Cpno,Ccredit)	VALUES ('6','数据处理',NULL,4);
INSERT  INTO Course(Cno,Cname,Cpno,Ccredit)	VALUES ('7','Pascal语言',NULL,4);
 
UPDATE Course SET Cpno = '5' WHERE Cno = '1' 
UPDATE Course SET Cpno = '1' WHERE Cno = '3' 
UPDATE Course SET Cpno = '6' WHERE Cno = '4' 
UPDATE Course SET Cpno = '7' WHERE Cno = '5' 
UPDATE Course SET Cpno = '6' WHERE Cno = '7' 
 
SELECT * FROM Course
 
INSERT  INTO SC(Sno,Cno,Grade) VALUES ('201215121 ','1',92);
INSERT  INTO SC(Sno,Cno,Grade) VALUES ('201215121 ','2',85);
INSERT  INTO SC(Sno,Cno,Grade) VALUES ('201215121 ','3',88);
INSERT  INTO SC(Sno,Cno,Grade) VALUES ('201215122 ','2',90);
INSERT  INTO SC(Sno,Cno,Grade) VALUES ('201215122 ','3',80);

INSERT INTO SC VALUES('201215123','1',86);
INSERT INTO SC VALUES('201215123','2',88);
INSERT INTO SC VALUES('201215123','3',76);
INSERT INTO SC VALUES('201215123','4',96);
INSERT INTO SC VALUES('201215123','5',85);
INSERT INTO SC VALUES('201215123','6',83);
INSERT INTO SC VALUES('201215123','7',82);

INSERT INTO SC VALUES('201215128','2',86);
INSERT INTO SC VALUES('201215128','3',56);
INSERT INTO SC VALUES('201215128','4',66);
INSERT INTO SC VALUES('201215128','5',88);
INSERT INTO SC VALUES('201215128','6',84);
INSERT INTO SC VALUES('201215128','7',66);

INSERT INTO SC VALUES('201215125','1',86);

 
SELECT * FROM SC

其余三张表（Managetable，Usertable，SchLog）建表代码：
（数据为自动写入）

CREATE TABLE Usertable         
(	 
	Uidentity NCHAR(20),   /*身份*/
	Uname NCHAR(20) PRIMARY KEY,    /*用户名*/    主码                  
	Upassword NCHAR(32) ,             /*密码*/
	Uid NCHAR(20),			/*工号/学号*/
	Unumber NCHAR(11),		/*电话号码*/
	Ubirthday datetime,			/*生日*/
 );
CREATE TABLE Managetable         
(	 
	Midentity NCHAR(20), 
	Mname NCHAR(20) PRIMARY KEY,                          
	Mpassword NCHAR(32) ,             
	Mid NCHAR(20),
	Mnumber NCHAR(11),
	Mbirthday datetime,
 );

 CREATE TABLE SchLog
 {
	id varchar(20);  /*登入名即为Managetable和Usertable的用户名*/
	DateAndTime datetime; /*登入时间*/
	UserOperation varchar(200); 
 };

表中数据显示

SELECT *FROM SC;
SELECT *FROM Student;
SELECT *FROM Course;
SELECT *FROM Managetable;
SELECT *FROM Usertable;
SELECT *FROM SchLog;

执行结果：

1.FormForget（忘记密码界面）

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Loginupdate
{
    public partial class FormForget : Form
    {
        public FormForget()
        {
            InitializeComponent();
        }
        class MyException : Exception
        {
            public MyException(string message) : base(message)
            {
            }
        }
        private void button1_Click(object sender, EventArgs e)
        {
            string identity = comboBox1.Text.Trim();
            string username = textBoxUserName.Text.Trim();  //取出账号
            string userid = textBox1.Text.Trim();
            string password = EncryptWithMD5(textBoxPassWord.Text.Trim());  //新密码-取出密码并加密
            string password1 = EncryptWithMD5(textBox2.Text.Trim());  //确认密码-取出密码并加密

            string myConnString = "Data Source=.;Initial Catalog=School;Persist Security Info=True;User ID=sa;Password=sa";
            SqlConnection sqlConnection = new SqlConnection(myConnString);
            sqlConnection.Open();
            string sql;
            if (comboBox1.Text.Equals("用户")) //判断身份
            {
                sql = "select Uname,Uid from Usertable where Uname = '" + username + "' and Uid = '" + userid + "'";
            }
            else
            {
                sql = "select Mid,Mid from Managetable where Mname = '" + username + "' and Mid = '" + userid + "'";
            }
            SqlCommand sqlCommand = new SqlCommand(sql, sqlConnection);
            SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();

            if (sqlDataReader.HasRows)//是否存在
            {
                sqlDataReader.Close();
                if (comboBox1.Text.Equals("管理员"))
                {
                    try
                    {
                        if (!password.Equals(password1))
                        {
                            string message = null;
                            if (message == null)
                            {
                                throw new MyException("前后两次输入的密码不一样！");
                            }
                        }
                        string sql1 = "UPDATE  Managetable SET Mpassword = '" + password + "'WHERE Mname = '" + username + "' AND Mid = '" + userid + "'";
                        sqlCommand = new SqlCommand(sql1, sqlConnection);
                        sqlCommand.ExecuteNonQuery();

                        MessageBox.Show("修改成功！");
                    }
                    catch (MyException myException)
                    {
                        MessageBox.Show(myException.Message);
                    }
                    catch
                    {
                        MessageBox.Show("输入数据违反要求!");
                    }
                    finally
                    {
                        sqlConnection.Close();
                    }
                }
                else
                {
                    try
                    {
                        if (!password.Equals(password1))
                        {
                            string message = null;
                            if (message == null)
                            {
                                throw new MyException("前后两次输入的密码不一样！");
                            }
                        }

                        string sql2 = "UPDATE  Usertable SET Upassword = '" + password + "'WHERE Uname = '" + username + "' AND Uid = '" + userid + "'";
                        sqlCommand = new SqlCommand(sql2, sqlConnection);
                        sqlCommand.ExecuteNonQuery();
                        MessageBox.Show("修改成功！");
                    }
                    catch (MyException myException)
                    {
                        MessageBox.Show(myException.Message);
                    }
                    catch
                    {
                        MessageBox.Show("输入数据违反要求!");
                    }
                    finally
                    {
                        sqlConnection.Close();
                    }
                }
            }
            else
            {
                MessageBox.Show("不存在此用户！");
                return;
            }
        }
        public static string EncryptWithMD5(string source) //MD5算法
        {
            byte[] sor = Encoding.UTF8.GetBytes(source);
            MD5 md5 = MD5.Create();
            byte[] result = md5.ComputeHash(sor);
            StringBuilder strbul = new StringBuilder(40);
            for (int i = 0; i < result.Length; i++)
            {
                strbul.Append(result[i].ToString("x2"));//加密结果"x2"结果为32位,"x3"结果为48位,"x4"结果为64位
            }
            return strbul.ToString();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            FormLogin formLogin = new FormLogin();
            this.Hide();
            formLogin.Show();
        }

    }
}

2.FormRegister （管理员用户注册界面）

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Loginupdate
{
    public partial class FormRegister : Form
    {
        public FormRegister()
        {
            InitializeComponent();
        }

        private void buttonOk_Click(object sender, EventArgs e)
        {
            string Rname = textBoxRname.Text.Trim();
            string Rpassword = EncryptWithMD5(textBoxRpassword.Text.Trim());
            string Rid = textBoxRid.Text.Trim();
            string Rnumber = textBoxRnumber.Text.Trim();
            string Ridentity = comboBox1.Text.Trim();
            DateTime Rdate = dateTimePicker.Value;

            if (Ridentity.Equals("") | Rname.Equals("") | Rpassword.Equals("") | Rid.Equals("") | Rnumber.Equals("") | Ridentity.Equals(""))
            {
                MessageBox.Show("请输入完整");
            }
            string myConnString = "Data Source=.;Initial Catalog=School;Persist Security Info=True;User ID=sa;Password=sa";
            if (Ridentity.Equals("管理员"))
            {
                SqlConnection sqlConnection = new SqlConnection(myConnString);  //实例化连接对象
                sqlConnection.Open();
                try
                {
                    string sql = "INSERT INTO  Managetable " +
                         "VALUES ('" + Ridentity + "','" + Rname + "','" + Rpassword + "','" + Rid + "','" + Rnumber + "','" + Rdate + "')";//+ "','" + image

                    SqlCommand sqlCommand = new SqlCommand(sql, sqlConnection);
                    SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
                    sqlConnection.Close();
                    MessageBox.Show("注册成功！");
                }
                catch
                {
                    MessageBox.Show("输入数据违反要求!");
                }
                finally
                {
                    sqlConnection.Close();
                }
            }
            else if (Ridentity.Equals("用户"))
            {
                SqlConnection sqlConnection = new SqlConnection(myConnString);  //实例化连接对象
                sqlConnection.Open();
                try
                {

                    string sql = "INSERT INTO  Usertable(Uidentity,Uname,Upassword,Uid,Unumber,Ubirthday)" +
                        "VALUES ('" + Ridentity + "','" + Rname + "','" + Rpassword + "','" + Rid + "','" + Rnumber + "','" + Rdate + "')";

                    SqlCommand sqlCommand = new SqlCommand(sql, sqlConnection);
                    SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
                    sqlConnection.Close();
                    MessageBox.Show("注册成功！");
                }
                catch
                {
                    MessageBox.Show("输入数据违反要求!");
                }
                finally
                {
                    sqlConnection.Close();
                }
            }
            else
                MessageBox.Show("请选择正确的身份");
            SqlConnection sqlConnection1 = new SqlConnection(myConnString);  //实例化连接对象
            string sql1 = "insert into SchLog values ( '" + Rname + "' , '" + DateTime.Now + "' , '" + "Login" + "')";
            SqlCommand sqlCommand1 = new SqlCommand(sql1, sqlConnection1);//编写SQL命令
            sqlCommand1 = new SqlCommand(sql1, sqlConnection1);

            SqlConnection sqlConnection2 = new SqlConnection(myConnString);  //实例化连接对象
            string sql2 = "insert into Account values ( '" + Rname + "' , '" + Rpassword + "')";
            sqlCommand1 = new SqlCommand(sql2, sqlConnection1);


            sqlConnection1.Close();

        }
        public static string EncryptWithMD5(string source)
        {
            byte[] sor = Encoding.UTF8.GetBytes(source);
            MD5 md5 = MD5.Create();
            byte[] result = md5.ComputeHash(sor);
            StringBuilder strbul = new StringBuilder(40);
            for (int i = 0; i < result.Length; i++)
            {
                strbul.Append(result[i].ToString("x2"));//加密结果"x2"结果为32位,"x3"结果为48位,"x4"结果为64位
            }
            return strbul.ToString();
        }
        public Byte[] mybyte = new byte[0];
        private void buttonCancel_Click(object sender, EventArgs e)
        {
            this.Hide();
            FormLogin formLogin = new FormLogin();
            formLogin.Show();
        }

        private void labelRpassword_Click(object sender, EventArgs e)
        {

        }
    }
}

3.FormLogin（登录界面）

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Loginupdate
{
    public partial class FormLogin : Form
    {
        public FormLogin()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {

            if (comboBox1.Text.Trim().Equals(""))  //提示选择身份
            {
                MessageBox.Show("请选择身份");
            }

            string username = textBoxUserName.Text.Trim();  //取出账号
            string password = EncryptWithMD5(textBoxPassWord.Text.Trim());  //取出密码并加密

            FormMainUser.sno = textBox1.Text.Trim(); //FormMainUser获取学号

            string myConnString = "Data Source=.;Initial Catalog=School;Persist Security Info=True;User ID=sa;Password=sa";

            SqlConnection sqlConnection = new SqlConnection(myConnString);  //实例化连接对象
            sqlConnection.Open();
            string sql;
            if (comboBox1.Text.Equals("用户"))
            {
                sql = "select Uname,Upassword from Usertable where Uname = '" + username + "' and Upassword = '" + password + "'";
            }
            else
            {
                sql = "select Mid,Mpassword from Managetable where Mname = '" + username + "' and Mpassword = '" + password + "'";
            }

            SqlCommand sqlCommand = new SqlCommand(sql, sqlConnection);

            SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();


            if (sqlDataReader.HasRows) 
            {
                if (textBoxCheckCode.Text == code)
                {
                    if (comboBox1.Text.Equals("管理员"))
                    {
                        sqlDataReader.Close();
                        sql = "insert into SchLog values ( '" + username + "' , '" + DateTime.Now + "' , '" + "Login" + "')";                                            //编写SQL命令
                        sqlCommand = new SqlCommand(sql, sqlConnection);
                        sqlCommand.ExecuteNonQuery();
                        sqlConnection.Close();
                        MessageBox.Show("欢迎你，管理员：" + username);
                        FormManage formManage = new FormManage();
                        this.Hide();
                        formManage.Show();
                    }
                    else
                    {
                        sqlDataReader.Close();
                        sql = "insert into SchLog values ( '" + username + "' , '" + DateTime.Now + "' , '" + "Login" + "')";                                            //编写SQL命令
                        sqlCommand = new SqlCommand(sql, sqlConnection);
                        sqlCommand.ExecuteNonQuery();
                        sqlConnection.Close();
                        MessageBox.Show("欢迎你，用户：" + username);
                        FormUser formUser = new FormUser();
                        this.Hide();
                        formUser.Show();
                    }
                }
            }
            else
            {
                MessageBox.Show("登录失败！");
                return;
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
        public string code;
        private void FormLogin_Load(object sender, EventArgs e)
        {
            Random ran = new Random();
            int number;
            char code1;
            this.code = "";
            for (int i = 0; i < 5; i++)//取五个数 
            {
                number = ran.Next();
                if (number % 2 == 0)
                    code1 = (char)('0' + (char)(number % 10));
                else
                    code1 = (char)('A' + (char)(number % 26)); //转化为字符 

                this.code += code1.ToString();
            }

            label5.Text = code;

        }
        public static string EncryptWithMD5(string source)
        {
            byte[] sor = Encoding.UTF8.GetBytes(source);
            MD5 md5 = MD5.Create();
            byte[] result = md5.ComputeHash(sor);
            StringBuilder strbul = new StringBuilder(40);
            for (int i = 0; i < result.Length; i++)
            {
                strbul.Append(result[i].ToString("x2"));//加密结果"x2"结果为32位,"x3"结果为48位,"x4"结果为64位
            }
            return strbul.ToString();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            FormRegister formRegister = new FormRegister();
            formRegister.ShowDialog();
            this.Hide();
        }

        private void button4_Click(object sender, EventArgs e)
        {

            this.FormLogin_Load(sender, e);
        }

        private void button6_Click(object sender, EventArgs e)
        {
            FormForget formForget = new FormForget();
            this.Hide();
            formForget.Show();
        }
    }
}

3.1-FormManage（管理员操作界面）

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Loginupdate
{
    public partial class FormManage : Form
    {
        public FormManage()
        {
            InitializeComponent();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            FormCourse formCourse = new FormCourse();
            formCourse.Show();
            this.Hide();
        }

        private void button5_Click(object sender, EventArgs e)
        {
            this.Hide();
            FormLogin formLogin = new FormLogin();
            formLogin.Show();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            FormLog formLog = new FormLog();
            formLog.Show();
            this.Hide();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            FormMain formMain = new FormMain();
            formMain.Show();
            this.Hide();
        }

        private void button4_Click(object sender, EventArgs e)
        {
            FormSC formSC = new FormSC();
            formSC.Show();
            this.Hide();
        }

        private void FormManage_Load(object sender, EventArgs e) //自动显示照片
        {
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }

    }
}

3.1.1-FormLog（查看登录日志）

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Loginupdate
{
    public partial class FormLog : Form
    {
        public FormLog()
        {
            InitializeComponent();
        }

        private void FormLog_Load(object sender, EventArgs e)
        {
            // TODO: 这行代码将数据加载到表“schoolDataSet7.SchLog”中。您可以根据需要移动或删除它。
            this.schLogTableAdapter.Fill(this.schoolDataSet7.SchLog);

        }

        private void button1_Click(object sender, EventArgs e)
        {
            this.Hide();
            FormManage formManage = new FormManage();
            formManage.Show();
        }

        private void fillByToolStripButton_Click(object sender, EventArgs e)
        {
            try
            {
                this.schLogTableAdapter.FillBy(this.schoolDataSet7.SchLog);
            }
            catch (System.Exception ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.Message);
            }

        }

        private void 最新登录日志ToolStripButton_Click(object sender, EventArgs e)
        {
            try
            {
                this.schLogTableAdapter.最新登录日志(this.schoolDataSet7.SchLog);
            }
            catch (System.Exception ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.Message);
            }

        }
    }
}

3.1.2-FormMain（管理员学生信息操作界面）

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 Loginupdate
{
    public partial class FormMain : Form
    {
        public FormMain()
        {
            InitializeComponent();
        }
        class MyException : Exception
        {
            public MyException(string message) : base(message)
            {
            }
        }
        private void FormMain_Load(object sender, EventArgs e)
        {
            // TODO: 这行代码将数据加载到表“schoolDataSet4.SC”中。您可以根据需要移动或删除它。
            this.sCTableAdapter.Fill(this.schoolDataSet4.SC);
            // TODO: 这行代码将数据加载到表“schoolDataSet3.Course”中。您可以根据需要移动或删除它。
            this.courseTableAdapter.Fill(this.schoolDataSet3.Course);
            // TODO: 这行代码将数据加载到表“schoolDataSet2.Student”中。您可以根据需要移动或删除它。
            this.studentTableAdapter.Fill(this.schoolDataSet2.Student);

        }

        private void buttonCLOSE_Click(object sender, EventArgs e)
        {
            this.Hide();
            FormManage formManage = new FormManage();
            formManage.Show();
        }
        SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=School;User ID=sa;Password=sa");
        private void buttonINSERT_Click(object sender, EventArgs e) //插入
        {
            String StuID = textBox1.Text.Trim();
            String StuName = textBox2.Text.Trim();
            String StuSex = textBox3.Text.Trim();
            String StuSdept = textBox4.Text.Trim();
            String StuAge = textBox5.Text.Trim();

            try
            {
                con.Open();
                string insertStr = "INSERT INTO  Student (Sno,Sname,Ssex,Sdept,Sage)    " +
                    "VALUES ('" + StuID + "','" + StuName + "','" + StuSex + "','" + StuSdept + "'," + StuAge + ")";
                SqlCommand cmd = new SqlCommand(insertStr, con);
                cmd.ExecuteNonQuery();
                MessageBox.Show("添加成功！");
            }
            catch
            {
                MessageBox.Show("输入数据违反要求!");
            }
            finally
            {
                con.Close();
            }
            this.studentTableAdapter.Fill(this.schoolDataSet2.Student);

        }

        private void buttonDELETE_Click(object sender, EventArgs e)//删除
        {
            try
            {
                con.Open();
                string select_id = dataGridView1.SelectedRows[0].Cells[0].Value.ToString();//选择的当前行第一列的值，也就是ID
                string delete_by_id = "delete from Student where Sno='" + select_id + "'";//sql删除语句
                SqlCommand cmd = new SqlCommand(delete_by_id, con);
                cmd.ExecuteNonQuery();
                MessageBox.Show("删除成功!");

            }
            catch
            {
                MessageBox.Show("请点击行最左侧进行删除!");
            }
            finally
            {
                con.Dispose();
            }
            this.studentTableAdapter.Fill(this.schoolDataSet2.Student);
        }

        private void buttonUPDATE_Click(object sender, EventArgs e)//修改
        {
            String StuID = textBox1.Text.Trim();
            String StuName = textBox2.Text.Trim();
            String StuSex = textBox3.Text.Trim();
            String StuSdept = textBox4.Text.Trim();
            String StuAge = textBox5.Text.Trim();

            try
            {
                if ((StuID == "") | (StuName == "") | (StuSex == "") | (StuSdept == "") | (StuAge == ""))
                {
                    string message = null;
                    if (message == null)
                    {
                        throw new MyException("输入不能为空");
                    }
                }

                con.Open();
                string insertStr = "UPDATE Student SET Sname = '" + StuName + "',Ssex = '" + StuSex + "',Sdept='" + StuSdept + "',Sage='" + StuAge + "' WHERE Sno = '" + StuID + "'";
                SqlCommand cmd = new SqlCommand(insertStr, con);
                cmd.ExecuteNonQuery();
                MessageBox.Show("修改成功!");

            }
            catch (MyException myException)
            {
                MessageBox.Show(myException.Message);
            }
            catch
            {
                MessageBox.Show("输入数据违反要求!");
            }
            finally
            {
                con.Close();
            }
            //}
            this.studentTableAdapter.Fill(this.schoolDataSet2.Student);
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
            textBox5.Text = "";
        }

        private void buttonSELECT_Click(object sender, EventArgs e)//查找
        {
            String StuID = textBox1.Text.Trim();
            String StuName = textBox2.Text.Trim();
            String StuSex = textBox3.Text.Trim();
            String StuSdept = textBox4.Text.Trim();
            String StuAge = textBox5.Text.Trim();
            try
            {
                String select_by_id = "select * from Student where ";
                int flag = 0;  //0是单条件，1是多条件
                con.Open();
                if (StuID != "")
                    select_by_id += "Sno='" + StuID + "'";    //单条件 按学号
                if (StuName != "")
                {
                    if (flag == 0)
                    {
                        select_by_id += "Sname LIKE'" + StuName + "'";
                        flag = 1;
                    }
                    if (flag == 1)
                        select_by_id += "And Sname LIKE'" + StuName + "'";

                }
                if (StuAge != "")
                {
                    if (flag == 0)
                    {
                        select_by_id += "Sage='" + StuAge + "'";
                        flag = 1;
                    }
                    if (flag == 1)
                        select_by_id += "And Sage='" + StuAge + "'";
                }
                if (StuSdept != "")
                {
                    if (flag == 0)
                    {
                        select_by_id += "Sdept='" + StuSdept + "'";
                        flag = 1;
                    }
                    if (flag == 1)
                        select_by_id += "And Sdept='" + StuSdept + "'";
                }
                if (StuSex != "")
                {
                    if (flag == 0)
                    {
                        select_by_id += "Ssex='" + StuSex + "'";
                        flag = 1;
                    }
                    if (flag == 1)
                        select_by_id += "And Ssex='" + StuSex + "'";
                }
                SqlCommand sqlCommand = new SqlCommand(select_by_id, con);
                SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
                BindingSource bindingSource = new BindingSource();
                bindingSource.DataSource = sqlDataReader;
                dataGridView1.DataSource = bindingSource;
            }

            catch
            {
                MessageBox.Show("查询语句有误，请认真检查SQL语句!");
            }
            finally
            {
                con.Close();
            }
            this.studentTableAdapter.Fill(this.schoolDataSet2.Student);
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
            textBox5.Text = "";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
            textBox5.Text = "";
            SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=School;User ID=sa;Password=sa");

            try
            {
                String select_by_id = "select * from Student";

                con.Open();
                SqlCommand sqlCommand = new SqlCommand(select_by_id, con);
                SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
                BindingSource bindingSource = new BindingSource();
                bindingSource.DataSource = sqlDataReader;
                dataGridView1.DataSource = bindingSource;
            }
            catch
            {
                MessageBox.Show("查询语句有误，请认真检查SQL语句!");
            }
            finally
            {
                con.Close();
            }


        }
    }
}

3.1.3-FormCourse（管理员课程管理界面）

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 Loginupdate
{
    public partial class FormCourse : Form
    {
        public FormCourse()
        {
            InitializeComponent();
        }

        class MyException : Exception
        {
            public MyException(string message) : base(message)
            {
            }
        }
        private void FormCourse_Load(object sender, EventArgs e)
        {
            // TODO: 这行代码将数据加载到表“schoolDataSet5.Course”中。您可以根据需要移动或删除它。
            this.courseTableAdapter.Fill(this.schoolDataSet5.Course);

        }

        private void buttonCLOSE_Click(object sender, EventArgs e)
        {
            this.Hide();
            FormManage formManage = new FormManage();
            formManage.Show();
        }
        SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=School;User ID=sa;Password=sa");
        private void buttonINSERT_Click(object sender, EventArgs e) // 插入
        {
            String Cno = textBox1.Text.Trim();
            String Cname = textBox2.Text.Trim();
            String Cpno = textBox3.Text.Trim();
            String Ccredit = textBox4.Text.Trim();
            string insertStr;
            try
            {
                con.Open();
                if (Cpno.Equals(""))
                {
                    insertStr = "INSERT INTO  Course (Cno,Cname,Ccredit) " +
                    "VALUES ('" + Cno + "','" + Cname + "','" + Ccredit + "')";
                }
                else
                {
                    insertStr = "INSERT INTO  Course (Cno,Cname,Cpno,Ccredit) " +
                   "VALUES ('" + Cno + "','" + Cname + "','" + Cpno + "','" + Ccredit + "')";
                }

                SqlCommand cmd = new SqlCommand(insertStr, con);
                cmd.ExecuteNonQuery();
                MessageBox.Show("添加成功！");
            }
            catch
            {
                MessageBox.Show("输入数据违反要求!");
            }
            finally
            {
                con.Close();
            }
            this.courseTableAdapter.Fill(this.schoolDataSet5.Course);
        }

        private void buttonDELETE_Click(object sender, EventArgs e)
        {
            try
            {
                con.Open();
                string select_Cno = dataGridView1.SelectedRows[0].Cells[0].Value.ToString();//选择的当前行第一列的值，也就是ID
                string select_Cpno = dataGridView1.SelectedRows[0].Cells[2].Value.ToString();//选择的当前行第一列的值，也就是ID
                string delete_by_Cno = "delete from Course where Cno='" + select_Cno + "'AND Cpno='" + select_Cpno + "'";//sql删除语句
                SqlCommand cmd = new SqlCommand(delete_by_Cno, con);
                cmd.ExecuteNonQuery();
                MessageBox.Show("删除成功!");

            }
            catch
            {
                MessageBox.Show("请点击行最左侧进行删除!");
            }
            finally
            {
                con.Close();
            }
            this.courseTableAdapter.Fill(this.schoolDataSet5.Course);
        }

        private void buttonUPDATE_Click(object sender, EventArgs e)//修改--全部输入以修改
        {
            String Cno = textBox1.Text.Trim();
            String Cname = textBox2.Text.Trim();
            String Cpno = textBox3.Text.Trim();
            String Ccredit = textBox4.Text.Trim();

            try
            {
                if ((Cno == "") | (Cname == "") | (Cpno == "") | (Ccredit == ""))
                {
                    string message = null;
                    if (message == null)
                    {
                        throw new MyException("输入不能为空");
                    }
                }
                con.Open();
                string insertStr = "UPDATE Course SET Cname = '" + Cname + "',Ccredit='" + Ccredit + "'WHERE Cno = '" + Cno + "'";// +"'AND Cpno='" +Cpno+ "'";
                SqlCommand cmd = new SqlCommand(insertStr, con);
                cmd.ExecuteNonQuery();
                MessageBox.Show("修改成功!");
            }
            catch (MyException myException)
            {
                MessageBox.Show(myException.Message);
            }
            catch
            {
                MessageBox.Show("输入数据违反要求!");
            }
            finally
            {
                con.Close();
            }
            this.courseTableAdapter.Fill(this.schoolDataSet5.Course);
        }

        private void buttonSELECT_Click(object sender, EventArgs e)//查找
        {
            String Cno = textBox1.Text.Trim();
            String Cname = textBox2.Text.Trim();
            String Cpno = textBox3.Text.Trim();
            String Ccredit = textBox4.Text.Trim();
           
            try
            {
                String select_by_id = "select * from Course where ";
                int flag = 0;  //0是单条件，1是多条件
                con.Open();
                if (Cno != "")
                    select_by_id += "Cno='" + Cno + "'";    //单条件 按学号
                if (Cname != "")
                {
                    if (flag == 0)
                    {
                        select_by_id += "Cname LIKE'" + Cname + "'";
                        flag = 1;
                    }
                    if (flag == 1)
                        select_by_id += "And Cname LIKE'" + Cname + "'";
                }
                if (Cpno != "")
                {
                    if (flag == 0)
                    {
                        select_by_id += "Cpno='" + Cpno + "'";
                        flag = 1;
                    }
                    if (flag == 1)
                        select_by_id += "And Cpno='" + Cpno + "'";
                }
                if (Ccredit != "")
                {
                    if (flag == 0)
                    {
                        select_by_id += "Ccredit='" + Ccredit + "'";
                        flag = 1;
                    }
                    if (flag == 1)
                        select_by_id += "And Ccredit='" + Ccredit + "'";
                }

                SqlCommand sqlCommand = new SqlCommand(select_by_id, con);
                SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
                BindingSource bindingSource = new BindingSource();
                bindingSource.DataSource = sqlDataReader;
                dataGridView1.DataSource = bindingSource;
            }
            catch
            {
                MessageBox.Show("查询语句有误，请认真检查SQL语句!");
            }
            finally
            {
                con.Close();
            }
            this.courseTableAdapter.Fill(this.schoolDataSet5.Course);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            textBox4.Text = "";
            SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=School;User ID=sa;Password=sa");

            try
            {
                String select_by_id = "select * from course";

                con.Open();
                SqlCommand sqlCommand = new SqlCommand(select_by_id, con);
                SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
                BindingSource bindingSource = new BindingSource();
                bindingSource.DataSource = sqlDataReader;
                dataGridView1.DataSource = bindingSource;
            }
            catch
            {
                MessageBox.Show("查询语句有误，请认真检查SQL语句!");
            }
            finally
            {
                con.Close();
            }
        }
    }
}

3.1.4-FormSC（管理员学生成绩操作界面）

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 Loginupdate
{
    public partial class FormSC : Form
    {
        public FormSC()
        {
            InitializeComponent();
        }
        class MyException : Exception
        {
            public MyException(string message) : base(message)
            {
            }
        }
        private void FormSC_Load(object sender, EventArgs e)
        {
            // TODO: 这行代码将数据加载到表“schoolDataSet6.SC”中。您可以根据需要移动或删除它。
            this.sCTableAdapter.Fill(this.schoolDataSet6.SC);

        }

        private void buttonCLOSE_Click(object sender, EventArgs e)
        {
            this.Hide();
            FormManage formManage = new FormManage();
            formManage.Show();
        }
        SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=School;User ID=sa;Password=sa");
        private void buttonINSERT_Click(object sender, EventArgs e)
        {
            String Sno = textBox1.Text.Trim();
            String Cno = textBox2.Text.Trim();
            String Grade = textBox3.Text.Trim();

            try
            {
                con.Open();
                string insertStr = "INSERT INTO  SC (Sno,Cno,Grade) " +
                    "VALUES ('" + Sno + "','" + Cno + "','" + Grade + "')";
                SqlCommand cmd = new SqlCommand(insertStr, con);
                cmd.ExecuteNonQuery();
                MessageBox.Show("添加成功！");
            }
            catch
            {
                MessageBox.Show("输入数据违反要求!");
            }
            finally
            {
                con.Close();
            }
            this.sCTableAdapter.Fill(this.schoolDataSet6.SC);
        }

        private void buttonDELETE_Click(object sender, EventArgs e) ///删除
        {
            String Sno = textBox1.Text.Trim();
            String Cno = textBox2.Text.Trim();
            String Grade = textBox3.Text.Trim();
            try
            {
                con.Open();
                string select_Sno = dataGridView1.SelectedRows[0].Cells[0].Value.ToString();//选择的当前行第一列的值，也就是ID
                string select_Cno = dataGridView1.SelectedRows[0].Cells[0].Value.ToString();
                string delete_by_id = "delete from SC where Sno='" + select_Sno + "'AND Cno='" + Cno + "'";//sql删除语句
                SqlCommand cmd = new SqlCommand(delete_by_id, con);
                cmd.ExecuteNonQuery();
                MessageBox.Show("删除成功!");

            }
            catch
            {
                MessageBox.Show("请点击行最左侧进行删除!");
            }
            finally
            {
                con.Dispose();
            }
            this.sCTableAdapter.Fill(this.schoolDataSet6.SC);
        }

        private void buttonUPDATE_Click(object sender, EventArgs e) //修改
        {
            String Sno = textBox1.Text.Trim();
            String Cno = textBox2.Text.Trim();
            String Grade = textBox3.Text.Trim();
            
            try
            {
                if ((Sno == "") | (Cno == "") | (Grade == ""))
                {
                    string message = null;
                    if (message == null)
                    {
                        throw new MyException("输入不能为空");
                    }
                }
                con.Open();
                string insertStr = "UPDATE SC SET Grade = '" + Grade + "' WHERE Sno = '" + Sno + "'AND Cno ='" + Cno + "'";
                SqlCommand cmd = new SqlCommand(insertStr, con);
                cmd.ExecuteNonQuery();
                
            }
            catch (MyException myException)
            {
                MessageBox.Show(myException.Message);
            }
            catch
            {
                MessageBox.Show("输入数据违反要求!");
            }
            finally
            {
                con.Close();
            }
            this.sCTableAdapter.Fill(this.schoolDataSet6.SC);
        }

        private void buttonSELECT_Click(object sender, EventArgs e) //查询
        {
            String Sno = textBox1.Text.Trim();
            String Cno = textBox2.Text.Trim();
            String Grade = textBox3.Text.Trim();
            
            try
            {
                String select_by_id = "select * from SC where ";
                int flag = 0;  //0是单条件，1是多条件
                con.Open();
                if (Sno != "")
                    select_by_id += "Sno='" + Sno + "'";    //单条件 按学号
                if (Cno != "")
                {
                    if (flag == 0)
                    {
                        select_by_id += "Cno LIKE'" + Cno + "'";
                        flag = 1;
                    }
                    if (flag == 1)
                        select_by_id += "And Cno LIKE'" + Cno + "'";

                }


                SqlCommand sqlCommand = new SqlCommand(select_by_id, con);
                SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
                BindingSource bindingSource = new BindingSource();
                bindingSource.DataSource = sqlDataReader;
                dataGridView1.DataSource = bindingSource;
            }
            catch
            {
                MessageBox.Show("查询语句有误，请认真检查SQL语句!");
            }
            finally
            {
                con.Close();
            }
            this.sCTableAdapter.Fill(this.schoolDataSet6.SC);
        }

        private void button1_Click(object sender, EventArgs e)
        {
            textBox1.Text = "";
            textBox2.Text = "";
            textBox3.Text = "";
            SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=School;User ID=sa;Password=sa");

            try
            {
                String select_by_id = "select * from SC";

                con.Open();
                SqlCommand sqlCommand = new SqlCommand(select_by_id, con);
                SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
                BindingSource bindingSource = new BindingSource();
                bindingSource.DataSource = sqlDataReader;
                dataGridView1.DataSource = bindingSource;
            }
            catch
            {
                MessageBox.Show("查询语句有误，请认真检查SQL语句!");
            }
            finally
            {
                con.Close();
            }
        }

        private void 学号_课程号ToolStripButton_Click(object sender, EventArgs e)
        {
            try
            {
                this.sCTableAdapter.学号_课程号(this.schoolDataSet6.SC);
            }
            catch (System.Exception ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.Message);
            }

        }

        private void 课程号_成绩ToolStripButton_Click(object sender, EventArgs e)
        {
            try
            {
                this.sCTableAdapter.课程号_成绩(this.schoolDataSet6.SC);
            }
            catch (System.Exception ex)
            {
                System.Windows.Forms.MessageBox.Show(ex.Message);
            }

        }

        private void 课程号_成绩ToolStrip_ItemClicked(object sender, ToolStripItemClickedEventArgs e)
        {

        }
    }
}

3.2-FormUser（用户操作界面）

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Loginupdate
{
    public partial class FormUser : Form
    {
        public FormUser()
        {
            InitializeComponent();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            FormCourseUser formCourseUser = new FormCourseUser();
            formCourseUser.Show();
            this.Hide();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            FormMainUser formMainUser = new FormMainUser();
            formMainUser.Show();
            this.Hide();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            this.Hide();
            FormLogin formLogin = new FormLogin();
            formLogin.Show();
        }

        private void label1_Click(object sender, EventArgs e)
        {

        }
    }
}

3.2.1-FormMainUser （用户查询操作&添加课程界面）

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 Loginupdate
{
    public partial class FormMainUser : Form
    {
        public FormMainUser()
        {
            InitializeComponent();
        }

        private void FormMainUser_Load(object sender, EventArgs e)
        {
            // TODO: 这行代码将数据加载到表“schoolDataSet8.SC”中。您可以根据需要移动或删除它。
            this.sCTableAdapter.Fill(this.schoolDataSet8.SC);

        }
        String conn = "Data Source=.;Initial Catalog=School;Persist Security Info=True;User ID=sa;Password=sa";
        private void button1_Click(object sender, EventArgs e)
        {

            SqlConnection sqlConnection = new SqlConnection(conn);  //实例化连接对象
            try
            {
                String select_by_id = "select * from SC where Sno='" + sno + "'";

                sqlConnection.Open();
                SqlCommand sqlCommand = new SqlCommand(select_by_id, sqlConnection);
                SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
                BindingSource bindingSource = new BindingSource();
                bindingSource.DataSource = sqlDataReader;
                this.dataGridView1.DataSource = bindingSource;
            }
            catch
            {
                MessageBox.Show("查询语句有误，请认真检查SQL语句!");
            }
            finally
            {
                sqlConnection.Close();
            }

        }

        public static string sno;

        private void button2_Click(object sender, EventArgs e)
        {
            this.Hide();
            FormUser formUser = new FormUser();
            formUser.Show();
        }

        private void button3_Click(object sender, EventArgs e)
        {

            String Cno = textBox2.Text.Trim();

            SqlConnection sqlConnection = new SqlConnection(conn);  //实例化连接对象
            try
            {
                sqlConnection.Open();
                string insertStr = "INSERT INTO  SC (Sno,Cno,Grade) " +
                    "VALUES ('" + sno + "','" + Cno + "'," + 0 + ")";
                SqlCommand cmd = new SqlCommand(insertStr, sqlConnection);
                cmd.ExecuteNonQuery();
                MessageBox.Show("添加成功！");
            }
            catch
            {
                MessageBox.Show("输入数据违反要求!");
            }
            finally
            {
                sqlConnection.Close();
            }
            this.sCTableAdapter.Fill(this.schoolDataSet8.SC);

        }

    }
}

3.2.2-FormCourseUser（用户查看所选课程界面）

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 Loginupdate
{
    public partial class FormCourseUser : Form
    {
        public FormCourseUser()
        {
            InitializeComponent();
        }

        private void FormCourseUser_Load(object sender, EventArgs e)
        {
            // TODO: 这行代码将数据加载到表“schoolDataSet9.Course”中。您可以根据需要移动或删除它。
            this.courseTableAdapter.Fill(this.schoolDataSet9.Course);

        }
        SqlConnection con = new SqlConnection("Data Source=.;Initial Catalog=School;User ID=sa;Password=sa");


        private void button3_Click(object sender, EventArgs e)
        {
            this.Hide();
            FormUser formUser = new FormUser();
            formUser.Show();
        }
    }
}

感悟

数据库终于做完了！一块石头落地！
本来我是信心满满，后来越做越不太情愿（拒绝的）的，当时什么也不懂，尤其是看到同学们都做好录屏之后，心里更是着急的鸭皮，事情就是这样，你需要以一个积极的心态，向上的信心慢慢地做，在过程中就会找到解决问题的方法，这也是自己一个成长的过程。

比如大实验之前，我对SQL与C#的了解不熟，C#需要先连接数据库，再执行每一个事务，dispose和close什么时候该用哪个？这得看具体情况，比如我重复执行那个操作时，我选择dispose就会错误，但是close就是正确的。…

数据库大作业遇到的问题及解决方案：数据库大作业遇到的问题及解决方案
源代码下载打包：
链接：https://pan.baidu.com/s/1nEy-X26BBldyfKcXehverg
提取码：4tlq
视频地址：视频暂时还没录好 ，等录完把地址po在这里。