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C#对Access进行增删改查的完整示例

2016-08-18 15:22 781 查看

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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标签:  c access 增删改查