华南理工大学 考研复试计算机科学 2016年代码 C#简单代码

1.sql约束
where sname like ‘张_’
where sname like ‘张[0-9]’
int num not null check(num<=30)
sex char(2) not null check(sex in(‘男’,’女’))
check([EmpSex]=’男’ or [EmpSex]=’女’)

2.DBHelperSQL.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
//1.先导入必要的命名空间,3个
using System.Data;//DataTable
using System.Data.SqlClient;//SqlConnection的命名空间
using System.Windows.Forms;//MessageBox
namespace Demo2016
{
    public class DBHelperSQL
    {
        /// <summary>
        /// 连接字符串
        /// </summary>
        public static string connStr = @"server=WIN-RDJDM79VJSM;database=test2016;integrated security=true;";
        //加入@可以防止在转义的时候发生错误
        /// <summary>
        /// 连接实例初始值为空
        /// </summary>
        public static SqlConnection conn = null;
        /// <summary>
        /// 增删改
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="para"></param>
        public static void TableChange(string sql, SqlParameter[] para = null)
        {
            try
            {
                SqlCommand cmd = new SqlCommand(sql, DBHelperSQL.conn);
                if (para != null)
                    cmd.Parameters.AddRange(para);阿
                if (cmd.ExecuteNonQuery() > 0)//影响行数
                {
                    MessageBox.Show("操作成功！");
                }
                else
                {
                    MessageBox.Show("操作失败!\n请检查数据库中是否有该条数据！");
                }
            }catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
        }
        /// <summary>
        /// 查询
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="para"></param>
        /// <returns></returns>
        public static DataTable TableSelect(string sql, SqlParameter[] para = null)
        {
            try
            {
                DataTable dt = new DataTable();
                SqlCommand cmd = new SqlCommand(sql, DBHelperSQL.conn);
                if (para != null)
                    cmd.Parameters.AddRange(para);
                SqlDataAdapter da = new SqlDataAdapter(cmd);
                da.Fill(dt);
                return dt;

            }catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
                return null;//出现异常，返回空
            }
        }
    }
}

3.program.cs代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;

namespace Demo2016
{
    static class Program
    {
        /// <summary>
        /// 应用程序的主入口点
        /// </summary>
        [STAThread]
        static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            try
            {
                //产生一个实例
                DBHelperSQL.conn=new System.Data.SqlClient.SqlConnection(DBHelperSQL.connStr);
                DBHelperSQL.conn.Open();//打开数据库
            }catch(Exception ex)
            {
                MessageBox.Show(ex.Message);
            }
            Application.Run(new FormMain());
            DBHelperSQL.conn.Close();
        }
    }
}

4.formMain.cs代码

namespace Demo2016
{
   public partial class FormMain : Form
    {
        public FormMain()
        {
            InitializeComponent();
        }
        private void 信息查询ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FormSearch fs = new FormSearch();
            fs.MdiParent = this;// 指定查询界面的依赖容器是这个
            fs.Show();
        }
        private void 信息统计ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            FormStatistics fss = new FormStatistics();
            fss.MdiParent = this;
            fss.Show();
        }
        private void 学生表维护ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            btnUpdate fst = new btnUpdate();
            fst.MdiParent = this;
            fst.Show();
        }
        private void 退出?ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Application.Exit();
        }
    }
}

5.学生表维护代码

using System.Data.SqlClient;//添加命名空间

namespace Demo2016
{
    public partial class btnUpdate : Form
    {
        public btnUpdate()
        {
            InitializeComponent();
        }

        private void btnAdd_Click(object sender, EventArgs e)
        {
            string sql = @"INSERT INTO [test2016].[dbo].[Student]
                               ([SNo]
                               ,[SName]
                               ,[Date]
                               ,[ClassNo])
                         VALUES(@SNo,@SName,@Date,@ClassNo)";
            SqlParameter[] para ={new SqlParameter("@SNo",txtSNo.Text),
                                new SqlParameter("@SName",txtSName.Text),
                                new SqlParameter("@Date",txtSDate.Text),
                                new SqlParameter("@ClassNo",txtClassNo.Text)};
            DBHelperSQL.TableChange(sql,para);
            MyShow();
        }

        private void btnDelete_Click(object sender, EventArgs e)
        {
            string sql = @"DELETE FROM [test2016].[dbo].[Student]
                                  WHERE [SNo] = @SNo";
            SqlParameter[] para ={new SqlParameter("@SNo",txtSNo.Text)};
            DBHelperSQL.TableChange(sql, para);
            MyShow();
        }

        private void btnSelect_Click(object sender, EventArgs e)
        {
            MyShow();
        }

        private void btnUpdate1_Click(object sender, EventArgs e)
        {
            string sql = @"UPDATE [test2016].[dbo].[Student]
                               SET [SName] = @SName
                                  ,[Date] = @Date
                                  ,[ClassNo] = @ClassNo
                             WHERE [SNo] = @SNo";
            SqlParameter[] para ={new SqlParameter("@SNo",txtSNo.Text),
                                new SqlParameter("@SName",txtSName.Text),
                                new SqlParameter("@Date",txtSDate.Text),
                                new SqlParameter("@ClassNo",txtClassNo.Text)};
            DBHelperSQL.TableChange(sql, para);
            MyShow();
        }
        public void MyShow()
        {
            string sql = @"SELECT [SNo]
                          ,[SName]
                          ,[Date]
                          ,[ClassNo]
                      FROM [test2016].[dbo].[Student]";
            dv.DataSource = DBHelperSQL.TableSelect(sql);
        }

        private void btnUpdate_Load(object sender, EventArgs e)
        {

        }
    }
}

6.查询统计代码

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

namespace Demo2016
{
    public partial class FormStatistics : Form
    {
        public FormStatistics()
        {
            InitializeComponent();
        }

        private void btn1_Click(object sender, EventArgs e)
        {
            string sql = @"select a.DeptNo 系编号,b.DeptName 系名称,SUM(a.Num) 总人数
                            from Class a,Department b
                            where a.DeptNo=b.DeptNo
                            group by a.DeptNo,b.DeptName";
            dv.DataSource = DBHelperSQL.TableSelect(sql);
        }

        private void btn2_Click(object sender, EventArgs e)
        {
            string sql = @"select CYear 入学年份,SUM(Num)总人数
                            from Class
                            group by CYear";
            dv.DataSource = DBHelperSQL.TableSelect(sql);
        }
    }
}

7.任意查询，组合查询

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;//添加

namespace Demo2016
{
    public partial class FormSearch : Form
    {
        public FormSearch()
        {
            InitializeComponent();
        }

        private void btn_Click(object sender, EventArgs e)
        {
            string sql = string.Format(@"select 
                            a.SName 名字,
                            b.SpecName 专业名称,
                            b.DeptNo 系编号
                            from Student a,Class b
                            where a.ClassNo=b.CNo and a.SName like '%{0}%'",txtSName.Text);
            if (chbSpecName.CheckState == CheckState.Checked)
            {
                sql += string.Format(@"and b.SpecName='{0}'", cboSpecName.SelectedValue.ToString());
            }
            if (chbDeptNo.CheckState == CheckState.Checked)
            {
                sql = sql + string.Format(@"and b.DeptNo='{0}'", cboDeptNo.SelectedValue.ToString());
            }
            if(chbName.CheckState==CheckState.Checked)
            {
                sql+=string.Format(@"and a.SName like '%{0}%'",txtSName.Text);
            }
            if (chbSpecName.CheckState == CheckState.Unchecked && chbDeptNo.CheckState == CheckState.Unchecked && chbName.CheckState == CheckState.Unchecked)
            {
                MessageBox.Show("您未选择任何勾选项！");
            }
            dv.DataSource = DBHelperSQL.TableSelect(sql);
        }

        private void FormSearch_Load(object sender, EventArgs e)
        {
            string sqlD = @"SELECT [DeptNo]
                                  ,[DeptName]
                              FROM [test2016].[dbo].[Department]";
            DataTable dtD = DBHelperSQL.TableSelect(sqlD);
            cboDeptNo.DataSource = dtD;
            cboDeptNo.DisplayMember = dtD.Columns["DeptNo"].ToString();
            cboDeptNo.ValueMember = dtD.Columns["DeptNo"].ToString();
            cboDeptNo.SelectedIndex = 0;

            string sqlS = @"SELECT [CNo]
                                      ,[SpecName]
                                      ,[Num]
                                      ,[CYear]
                                      ,[DeptNo]
                                  FROM [test2016].[dbo].[Class]";
            DataTable dtS = DBHelperSQL.TableSelect(sqlS);
            cboSpecName.DataSource = dtS;
            cboSpecName.DisplayMember = dtS.Columns["SpecName"].ToString();
            cboSpecName.ValueMember = dtS.Columns["SpecName"].ToString();
            cboSpecName.SelectedIndex = 0;         
        } 
    }
}

8.readme
1.附加数据库test201603.mdf
2.SQL文件夹下为数据库的所有操作
3.Info为数据库设计文档
4.修改DBhelperSQL.cs文件下的连接字符串使之适合自己的电脑
5.backinfo.bak为数据库备份文件
6.连接字符串:@”server=你的计算机全名;database=你的数据库名;integrated security=true;”;

9.info
基本信息
计算机全名:WIN-RDJDM79VJSM
windows身份验证方式
连接字符串:@”server=WIN-RDJDM79VJSM;database=test201603;integrated security=true;”;
数据库创建