C#对Access进行增删改查的完整示例

前端技术 2023/09/02 C#

这篇文章整理了C#对Access数据库的查询、添加记录、删除记录和更新数据等一系列的操作示例，有需要的可以参考学习。

首先是AccessHelper.cs，网上有下载，下面附送一份；

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Data.OleDb;
using System.Data;
using System.Windows.Forms;
 
namespace yxdain
{
  public class AccessHelper
  {
    private string conn_str = null;
    private OleDbConnection ole_connection = null;
    private OleDbCommand ole_command = null;
    private OleDbDataReader ole_reader = null;
    private DataTable dt = null;
 
    /// <summary>
    /// 构造函数
    /// </summary>
    public AccessHelper()
    {
      //conn_str = @\"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\'\" + Environment.CurrentDirectory + \"\\\\yxdain.accdb\'\";
      conn_str = @\"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=\'\" + Environment.CurrentDirectory + \"\\\\yxdain.accdb\'\";
       
      InitDB();
    }
 
    private void InitDB()
    {
      ole_connection =new OleDbConnection(conn_str);//创建实例
      ole_command =new OleDbCommand();
    }
 
    /// <summary>
    /// 构造函数
    /// </summary>
    ///<param name=\"db_path\">数据库路径
    public AccessHelper(string db_path)
    {
      //conn_str =\"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=\'\"+ db_path + \"\'\";
      conn_str = \"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=\'\" + db_path + \"\'\";
       
      InitDB();
    }
 
    /// <summary>
    /// 转换数据格式
    /// </summary>
    ///<param name=\"reader\">数据源
    /// <returns>数据列表</returns>
    private DataTable ConvertOleDbReaderToDataTable(ref OleDbDataReader reader)
    {
      DataTable dt_tmp =null;
      DataRow dr =null;
      int data_column_count = 0;
      int i = 0;
 
      data_column_count = reader.FieldCount;
      dt_tmp = BuildAndInitDataTable(data_column_count);
 
      if(dt_tmp == null)
      {
        return null;
      }
 
      while(reader.Read())
      {
        dr = dt_tmp.NewRow();
 
        for(i = 0; i < data_column_count; ++i)
        {
          dr[i] = reader[i];
        }
 
        dt_tmp.Rows.Add(dr);
      }
 
      return dt_tmp;
    }
 
    /// <summary>
    /// 创建并初始化数据列表
    /// </summary>
    ///<param name=\"Field_Count\">列的个数
    /// <returns>数据列表</returns>
    private DataTable BuildAndInitDataTable(int Field_Count)
    {
      DataTable dt_tmp =null;
      DataColumn dc =null;
      int i = 0;
 
      if(Field_Count <= 0)
      {
        return null;
      }
 
      dt_tmp =new DataTable();
 
      for(i = 0; i < Field_Count; ++i)
      {
        dc =new DataColumn(i.ToString());
        dt_tmp.Columns.Add(dc);
      }
 
      return dt_tmp;
    }
 
    /// <summary>
    /// 从数据库里面获取数据
    /// </summary>
    ///<param name=\"strSql\">查询语句
    /// <returns>数据列表</returns>
    public DataTable GetDataTableFromDB(string strSql)
    {
      if(conn_str == null)
      {
        return null;
      }
       
      try
      {
        ole_connection.Open();//打开连接
 
        if(ole_connection.State == ConnectionState.Closed)
        {
          return null;
        }
 
        ole_command.CommandText = strSql;
        ole_command.Connection = ole_connection;
 
        ole_reader = ole_command.ExecuteReader(CommandBehavior.Default);
 
        dt = ConvertOleDbReaderToDataTable(ref ole_reader);
 
        ole_reader.Close();
        ole_reader.Dispose();
      }
      catch(System.Exception e)
      {
        //Console.WriteLine(e.ToString());
        MessageBox.Show(e.Message);
      }
      finally
      {
        if(ole_connection.State != ConnectionState.Closed)
        {
          ole_connection.Close();
        }
      }
       
      return dt;
    }
 
    /// <summary>
    /// 执行sql语句
    /// </summary>
    ///<param name=\"strSql\">sql语句
    /// <returns>返回结果</returns>
    public int ExcuteSql(string strSql)
    {
      int nResult = 0;
 
      try
      {
        ole_connection.Open();//打开数据库连接
        if(ole_connection.State == ConnectionState.Closed)
        {
          return nResult;
        }
 
        ole_command.Connection = ole_connection;
        ole_command.CommandText = strSql;
 
        nResult = ole_command.ExecuteNonQuery();
      }
      catch(System.Exception e)
      {
        //Console.WriteLine(e.ToString());
        MessageBox.Show(e.Message);
        return nResult;
      }
      finally
      {
        if(ole_connection.State != ConnectionState.Closed)
        {
          ole_connection.Close();
        }
      }
 
      return nResult;
    }
  }
}

定义变量，设置列标题；

private AccessHelper achelp;
......
  private void Form1_Load(object sender, EventArgs e)
  {
 
    achelp = new AccessHelper();
    string sql1 = \"select * from ycyx\";
    databind1(sql1);
    
    dataGridView1.Columns[0].Visible = false;
    dataGridView1.Columns[1].HeaderCell.Value = \"服务号码\";
    dataGridView1.Columns[2].HeaderCell.Value = \"客户名称\";
    dataGridView1.Columns[3].HeaderCell.Value = \"归属地区\";
    dataGridView1.Columns[4].HeaderCell.Value = \"当前品牌\";
    dataGridView1.Columns[5].HeaderCell.Value = \"当前套餐\";
    dataGridView1.Columns[6].HeaderCell.Value = \"当前状态\";
  }

显示数据表全部内容；

private void databind1(string sqlstr)
{
  DataTable dt = new DataTable();
  dt = achelp.GetDataTableFromDB(sqlstr);
  dataGridView1.DataSource = dt;
}

读取要更新记录到更新窗体控件；

private void button3_Click(object sender, EventArgs e)
{
  if (dataGridView1.SelectedRows.Count < 1 || dataGridView1.SelectedRows[0].Cells[1].Value == null)
  {
    MessageBox.Show(\"没有选中行。\", \"M营销\");
    return;
  }
  //f3.Owner = this;
  DataTable dt = new DataTable();
  object oid = dataGridView1.SelectedRows[0].Cells[0].Value;
  string sql = \"select * from ycyx where ID=\" + oid;
  dt = achelp.GetDataTableFromDB(sql);
  f3 = new Form3();
  f3.id = int.Parse(oid.ToString());
  //f3.id = 2;
  f3.Text1 = dt.Rows[0][1].ToString();
  f3.Text2 = dt.Rows[0][2].ToString();
  f3.Text3 = dt.Rows[0][3].ToString();
  f3.Text4 = dt.Rows[0][4].ToString();
  f3.Text5 = dt.Rows[0][5].ToString();
  f3.Text6 = dt.Rows[0][6].ToString();
 
  f3.ShowDialog();
   
}

添加记录；

private void button4_Click(object sender, EventArgs e)
{
  if (textBox1.Text == \"\" && textBox2.Text == \"\" && textBox3.Text == \"\" && textBox4.Text == \"\" && textBox5.Text == \"\" && textBox6.Text == \"\")
  {
    MessageBox.Show(\"没有要添加的内容\", \"M营销添加\");
    return;
  }
  else
  {
    string sql = \"insert into ycyx (fwhm,khmc,gsdq,dqpp,dqtc,dqzt) values (\'\" + textBox1.Text + \"\',\'\" + textBox2.Text + \"\',\'\"+
      textBox3.Text + \"\',\'\"+ textBox4.Text + \"\',\'\"+ textBox5.Text + \"\',\'\"+ textBox6.Text + \"\')\";
    int ret = achelp.ExcuteSql(sql);
    string sql1 = \"select * from ycyx\";
    databind1(sql1);
    textBox1.Text = \"\";
    textBox2.Text = \"\";
    textBox3.Text = \"\";
    textBox4.Text = \"\";
    textBox5.Text = \"\";
    textBox6.Text = \"\";
  }
}

删除记录；

private void button2_Click(object sender, EventArgs e)
{
  if (dataGridView1.SelectedRows.Count < 1 || dataGridView1.SelectedRows[0].Cells[1].Value == null)
  {
    MessageBox.Show(\"没有选中行。\", \"M营销\");
  }
  else
  {
    object oid = dataGridView1.SelectedRows[0].Cells[0].Value;
    if (DialogResult.No == MessageBox.Show(\"将删除第 \" + (dataGridView1.CurrentCell.RowIndex + 1).ToString() + \" 行，确定？\", \"M营销\", MessageBoxButtons.YesNo))
    {
      return;
    }
    else
    {
      string sql = \"delete from ycyx where ID=\" + oid;
      int ret = achelp.ExcuteSql(sql);
    }
    string sql1 = \"select * from ycyx\";
    databind1(sql1);
  }
}

查询；

private void button13_Click(object sender, EventArgs e)
{
  if (textBox23.Text == \"\")
  {
    MessageBox.Show(\"请输入要查询的当前品牌\", \"M营销\");
    return;
  }
  else
  {
    string sql = \"select * from ycyx where dqpp=\'\" + textBox23.Text + \"\'\";
    DataTable dt = new System.Data.DataTable();
    dt = achelp.GetDataTableFromDB(sql);
    dataGridView1.DataSource = dt;
  }
}

用户确定显示或不显示哪些数据列；

private void button15_Click(object sender, EventArgs e)
{
  if (checkBox1.Checked == true)
  {
    dataGridView1.Columns[1].Visible = true;
  }
  else
  {
    dataGridView1.Columns[1].Visible = false;
  }
 
  if (checkBox2.Checked == true)
  {
    dataGridView1.Columns[2].Visible = true;
  }
  else
  {
    dataGridView1.Columns[2].Visible = false;
  }
 
  if (checkBox3.Checked == true)
  {
    dataGridView1.Columns[3].Visible = true;
  }
  else
  {
    dataGridView1.Columns[3].Visible = false;
  }
 
  if (checkBox4.Checked == true)
  {
    dataGridView1.Columns[4].Visible = true;
  }
  else
  {
    dataGridView1.Columns[4].Visible = false;
  }
 
  if (checkBox5.Checked == true)
  {
    dataGridView1.Columns[5].Visible = true;
  }
  else
  {
    dataGridView1.Columns[5].Visible = false;
  }
 
  if (checkBox6.Checked == true)
  {
    dataGridView1.Columns[6].Visible = true;
  }
  else
  {
    dataGridView1.Columns[6].Visible = false;
  }
}

更新数据；

  public partial class Form3 : Form
  {
    private AccessHelper achelp;
    private int iid;
 
    public Form3()
    {
      InitializeComponent();
      achelp = new AccessHelper();
      iid = 0;
    }
 
    // 更新
    private void button1_Click(object sender, EventArgs e)
    {
      try
      {
        //UPDATE Person SET Address = \'Zhongshan 23\', City = \'Nanjing\'WHERE LastName = \'Wilson\'
        string sql = \"update ycyx set fwhm=\'\"+textBox1.Text+\"\',khmc=\'\"+textBox2.Text+\"\',gsdq=\'\"+textBox3.Text+\"\',dqpp=\'\"+textBox4.Text+
          \"\',dqtc=\'\"+textBox5.Text+\"\',dqzt=\'\"+textBox6.Text+\"\' where ID=\"+iid;
           
 
        int ret = achelp.ExcuteSql(sql);
        if (ret > -1)
        {
          this.Hide();
          MessageBox.Show(\"更新成功\", \"M营销\");
        }
      }
      catch (Exception ex)
      {
        MessageBox.Show(ex.Message);
      }
 
       
 
    }
 
    private void Form3_Load(object sender, EventArgs e)
    {
 
    }
 
    public int id
    {
      get { return this.iid; }
      set { this.iid = value; }
    }
 
 
    public string Text1
    {
      get { return this.textBox1.Text; }
      set { this.textBox1.Text = value; }
    }
 
    public string Text2
    {
      get { return this.textBox2.Text; }
      set { this.textBox2.Text = value; }
    }
 
    public string Text3
    {
      get { return this.textBox3.Text; }
      set { this.textBox3.Text = value; }
    }
 
    public string Text4
    {
      get { return this.textBox4.Text; }
      set { this.textBox4.Text = value; }
    }
 
    public string Text5
    {
      get { return this.textBox5.Text; }
      set { this.textBox5.Text = value; }
    }
 
    public string Text6
    {
      get { return this.textBox6.Text; }
      set { this.textBox6.Text = value; }
    }
 
    //取消
    private void button2_Click(object sender, EventArgs e)
    {
      this.Hide();
    }
  }
}

注意此处有一个技巧；C# Winform，在窗体之间传值，或在一个窗体中设置另一个窗体的控件的值时，有多种方式；最好方式是如上代码所示；使用.net的get、set属性； 

控件是一个窗体的私有变量，不能在另一个窗体中直接访问；为了在a窗体中设置b窗体的控件的值，对b窗体的控件都添加一个带get、set的公共属性，就可在a中设置b中控件的值，具体看代码；

以上就是C#对Access进行增删改查的完整示例代码，希望对大家学习C#能有所帮助。

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