多数据库的链接

1，首先定义一个数据库连接与操作的抽象类，这个里面写一些你需要用到的一些抽象方法。

然后就是对应你的数据库写与之对应的类并继承你说定义的抽象类，并重写抽象类里面的方法！

对应代码如下：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;


namespace DBASES
{
   public abstract class DBastr
    {
       abstract public int Insert(string number1,string operation, string number2);
       abstract public int Delect();
       abstract public DataTable Gettable();
       abstract public void Open();
       abstract public void Close();
    }
   public class TIASS : DBastr
   {
       public static string constr = "Data Source=.;Initial Catalog=TIASS;Integrated Security=True";
       SqlConnection conn = new SqlConnection(constr);
       public override void Open()
       {
           conn = new SqlConnection(constr);
           conn.Open();
       }
       public override void Close()
       {
           conn.Close();
       }
       public override int Insert(string number1, string operation, string number2)
       {
           string cmdstr = "insert into TI(number1,operation,number2) values ('"+number1+"','"+operation+"','"+number2+"')";
           Open();
           SqlCommand cmd = new SqlCommand(cmdstr, conn);
           int a = cmd.ExecuteNonQuery();
           Close();
           return a;
       }
       public override int Delect()
       {
           string cmdstr = "delete from TI";
           Open();
           SqlCommand cmd = new SqlCommand(cmdstr, conn);
           int a = cmd.ExecuteNonQuery();
           Close();
           return a;
       }
       public override DataTable Gettable()
       {
           string cmdstr = "select number1,operation, number2 from TI";
           SqlDataAdapter dat = new SqlDataAdapter(cmdstr,conn);
           DataTable dt = new DataTable();
           dat.Fill(dt);
           return dt;
       }
   }
   public class TIBD : DBastr
   {
      public static string constr = "Data Source=.;Initial Catalog=TIBD;Integrated Security=True";
       SqlConnection conn = new SqlConnection(constr);
       public override void Open()
       {
           conn.Open();
       }
       public override void Close()
       {
           conn.Close();
       }
       public override int Insert(string number1, string operation, string number2)
       {
           string cmdstr = "insert into TA(number1,operation,number2) values ('" + number1 + "','" + operation + "','" + number2 + "')";
           Open();
           SqlCommand cmd = new SqlCommand(cmdstr, conn);
           int a = cmd.ExecuteNonQuery();
           Close();
           return a;
           
       }
       public override int Delect()
       {
           string cmdstr = "delete from TA";
           Open();
           SqlCommand cmd = new SqlCommand(cmdstr, conn);
           int a = cmd.ExecuteNonQuery();
           Close();
           return a;
       }
       public override DataTable Gettable()
       {
           string cmdstr = "select number1,operation, number2 from TA";
           SqlDataAdapter dat = new SqlDataAdapter(cmdstr, conn);
           DataTable dt = new DataTable();
           dat.Fill(dt);
           return dt;
       }
 
   }
   public class Faction //定义工厂类
   {
       
       public DBastr dbastr;
       public DBastr GetDB(string DBtyle)
       {  
           switch (DBtyle)
           {
               case "TIASS":
                   dbastr = new TIASS();
                   break;
               case "TIDB":
                   dbastr = new TIBD();
                   break;
 
           }
           return dbastr;
           
       }
   }
}

然后定义计算所用的类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace DBASES
{
   
    interface Iation//定义计算接口
    {
        double Calation(double a, double b);
    }
    class Add : Iation//加法
    {
        public double Calation(double a, double b)
        {
            return a + b;
        }
    }
    class Sub : Iation//减法
    {
        public double Calation(double a, double b)
        {
            return a - b;
        }
    }
    class Mul : Iation//乘法
    {
        public double Calation(double a, double b)
        {
            return a * b;
        }
    }
    class Div : Iation//除法
    {
        public double Calation(double a, double b)
        {
            if (b == 0)
            {
                throw new Exception("除数不能为零！");
            }
            else
            {
                return a / b;
            }
        }
    }
    class Factionsss
    {
        private Iation clation;
        public Factionsss(string operation)
        {
            switch (operation)
            {
                case "+":
                    clation = new Add();
                    break;
                case "-":
                    clation = new Sub();
                    break;
                case "*":
                    clation = new Mul();
                    break;
                case "/":
                    clation = new Div();
                    break;
            }

        }
        public double cal(double a, double b)
        {
            return clation.Calation(a, b);
        }

    }
}

from1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 DBASES
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        Faction faction = new Faction();
        private void radioButton1_CheckedChanged(object sender, EventArgs e)
        {
            if (radioButton1.Checked == true)
            {
                label2.Text = "你选择了TIASS数据库！";
            }
        }

        private void radioButton2_CheckedChanged(object sender, EventArgs e)
        {
            if (radioButton2.Checked == true)
            {
                label2.Text = "你选择了TIDB数据库！";
            }
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (radioButton1.Checked == true)
            {
                
                int a = faction.GetDB("TIASS").Insert(textBox1.Text, comboBox1.Text, textBox2.Text);
                if (a > 0)
                {
                    MessageBox.Show("保存成功！");
                }
                else
                {
                    MessageBox.Show("保存失败!");
                }
                textBox1.Clear();
                textBox2.Clear();
 
            }
            else if (radioButton2.Checked == false)
            {
                MessageBox.Show("请选择你所要链接的数据库！");
            }
            else
            {
                
                int b = faction.GetDB("TIDB").Insert(textBox1.Text, comboBox1.Text, textBox2.Text);
                if (b > 0)
                {
                    MessageBox.Show("保存成功！");
                }
                else
                {
                    MessageBox.Show("保存失败！");
                }
                textBox1.Clear();
                textBox2.Clear();
            }
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (radioButton1.Checked == true)
            {
                int c = faction.GetDB("TIASS").Delect();
                if (c > 0)
                {
                    MessageBox.Show("删除成功！");
                }
                else
                {
                    MessageBox.Show("删除失败！");
                }
            }
            else if (radioButton2.Checked == true)
            {
                int d = faction.GetDB("TIDB").Delect();
                if (d > 0)
                {
                    MessageBox.Show("删除成功！");
                }
                else
                {
                    MessageBox.Show("删除失败！");
                }
            }
            else
            {
                MessageBox.Show("请选择你所要删除的数据！");
            }
        }

        private void button3_Click(object sender, EventArgs e)
        {
            Form2 fra = new Form2();
            fra.ShowDialog();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            radioButton1.Checked = true;
        }
    }
}

from1设计

from2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 DBASES
{
    public partial class Form2 : Form
    {
        public Form2()
        {
            InitializeComponent();
        }
        private int i = 0;
        Faction fation = new Faction();
        private void Form2_Load(object sender, EventArgs e)
        {
            radioButton1.Checked = true;
            i = 0;
            Read("TIASS");
            
            

        }
        public void Read(string DB)
        {
            
            DataTable dt = fation.GetDB(DB).Gettable();

            if (i <= dt.Rows.Count - 1)
            {
                textBox1.Text = dt.Rows[i][0].ToString().Trim();
                label1.Text = dt.Rows[i][1].ToString().Trim();
                textBox2.Text = dt.Rows[i][2].ToString().Trim();
                i++;
                
            }
            else
            {
                MessageBox.Show("本数据库题你做完了！");
 
            }
               
            
           
        }

        private void radioButton2_CheckedChanged(object sender, EventArgs e)
        {
            i = 0;
            Read("TIDB");
        }

        private void textBox3_KeyDown(object sender, KeyEventArgs e)
        {
            if (e.KeyCode == Keys.Enter)
            {
                double a = Convert.ToDouble(textBox1.Text);
                double b = Convert.ToDouble(textBox2.Text);
                string oper = label1.Text;
                Factionsss fas = new Factionsss(oper);
                double answer = fas.cal(a, b);
                if (textBox3.Text == answer.ToString())
                {
                    MessageBox.Show("回答正确！");
                }
                else
                {
                    MessageBox.Show("回答错误！");
                }
                textBox3.Clear();
                if (radioButton1.Checked == true)
                {
                    Read("TIASS");
                }
                else
                {
                    Read("TIDB");
                }
            }
        }

        private void radioButton1_CheckedChanged(object sender, EventArgs e)
        {
            i = 0;
            Read("TIASS");
        }
    }
}

from2设计

测试

TIASS数据库存题

TIDB数据库存题

TIASS数据库做题

TIDB数据库做题

多数据库的存题读题感觉很灵活，但是只能是表结构相同的情况下才能成功？

本来是想写一个可以两个数，三个数，四个数都可以选择的数据库存题读题。但是发现用这个方法无法实现！