C#数据库操作

来源：互联网发布：网络终端遗传因子编辑：程序博客网时间：2024/05/16 18:44
using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Data.OleDb;//连接Access数据库using System.Drawing;using System.Linq;using System.Text;using System.Windows.Forms;using System.Diagnostics;//调试输出Trace.WriteLinenamespace WindowsFormsApplication1{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        //连接数据库        OleDbConnection conn;        private void button1_Click(object sender, EventArgs e)        {            try            {                string ConStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=mine.mdb;Persist Security Info=False";                conn = new OleDbConnection(ConStr);                conn.Open();                if (conn.State == ConnectionState.Open)                {                    label1.Text = "连接数据库成功";                }            }            catch            {                MessageBox.Show("连接数据库失败");            }        }        //关闭数据库        private void button2_Click(object sender, EventArgs e)        {            try            {                conn.Close();                if (conn.State == ConnectionState.Closed)                {                    label1.Text = "关闭数据库成功";                }            }            catch            {                MessageBox.Show("关闭数据库失败");            }        }        //Command的用法--执行SQL语句        private void button3_Click(object sender, EventArgs e)        {            try            {                OleDbCommand cmd = new OleDbCommand();                             cmd.Connection = conn;                cmd.CommandText = "INSERT INTO info (Name, Age,Place) VALUES ('Wilson', '12','beijing')";                cmd.CommandType = CommandType.Text;                //int i = Convert.ToInt32(cmd.ExecuteNonQuery());                int i = cmd.ExecuteNonQuery();//返回受影响的行数                string iStr = string.Format("有{0}行受影响", i.ToString());                toolStripStatusLabel1.Text = iStr;            }            catch(Exception ex)            {                MessageBox.Show(ex.Message);            }        }        //DataReader对象是一个简单的数据集，用于从数据源中检索只读数据集，常用于检索大量数据。        private void button4_Click(object sender, EventArgs e)        {            try            {                OleDbCommand cmd = new OleDbCommand();                cmd.Connection = conn;                cmd.CommandText = "select * from info";                cmd.CommandType = CommandType.Text;                OleDbDataReader drNew = cmd.ExecuteReader();                string[] parm=new string[4];                if (drNew.HasRows)                {                    while (drNew.Read())                    {                        Trace.WriteLine(drNew[1]);                    }                }                drNew.Close();            }            catch (Exception ex)            {                MessageBox.Show(ex.Message);            }        }        //DataSet的创建。可以把DataSet当成内存中的数据库，DataSet是不依赖于数据库的独立数据集合        DataSet ds;        int i = 0;//当前行        int j = 0;//行数        DataTable dtInfo;        private void DisPlay()        {            DataRow dr = dtInfo.Rows[i];            textID.Text = dr[0].ToString();            textName.Text = dr[1].ToString();            textAge.Text = dr[2].ToString();            textPlace.Text = dr[3].ToString();        }        private void button5_Click(object sender, EventArgs e)        {            try            {                ds = new DataSet();                OleDbDataAdapter daNew = new OleDbDataAdapter("select * from info", conn);                daNew.Fill(ds);                toolStripStatusLabel1.Text = "创建DataSet成功！";            }            catch(Exception ex)            {                toolStripStatusLabel1.Text = ex.Message;            }            dtInfo = ds.Tables[0];            foreach (DataColumn dc in dtInfo.Columns)                Trace.WriteLine(dc.ColumnName);//调试输出列名            foreach (DataRow row in dtInfo.Rows)                Trace.WriteLine(row[0]);//调试输出第一列数据                        j = dtInfo.Rows.Count;//获取数据库的行数            DisPlay();        }        //向上翻页        private void button6_Click(object sender, EventArgs e)        {            if (i > 0)            {                i--;                DisPlay();            }            else            {                toolStripStatusLabel1.Text = "当前为第一页！";            }        }        //向下翻页        private void button7_Click(object sender, EventArgs e)        {            if (i < j-1)            {                i++;                DisPlay();            }            else                toolStripStatusLabel1.Text = "已到尾页！";        }        //添加数据        private void button8_Click(object sender, EventArgs e)        {            try            {                OleDbCommand cmd = new OleDbCommand();                cmd.Connection = conn;                string cmdStr = string.Format("INSERT INTO info (Name,Age,Place) VALUES ('{0}','{1}','{2}')", textName.Text, textAge.Text, textPlace.Text);                cmd.CommandType = CommandType.Text;                cmd.CommandText = cmdStr;                int i = cmd.ExecuteNonQuery();//返回受影响的行数                toolStripStatusLabel1.Text="添加数据成功！";                //更新数据库,与之前代码一样的                try                {                    if (conn.State == ConnectionState.Open)                    {                        conn.Close();                        string ConStr = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=mine.mdb;Persist Security Info=False";                        conn = new OleDbConnection(ConStr);                        conn.Open();                    }                }                catch                {                    MessageBox.Show("连接数据库失败");                }                try                {                    ds = new DataSet();                    OleDbDataAdapter daNew = new OleDbDataAdapter("select * from info", conn);                    daNew.Fill(ds);                    toolStripStatusLabel1.Text = "创建DataSet成功！";                }                catch (Exception ex)                {                    toolStripStatusLabel1.Text = ex.Message;                }                dtInfo = ds.Tables[0];                foreach (DataColumn dc in dtInfo.Columns)                    Trace.WriteLine(dc.ColumnName);//调试输出列名                foreach (DataRow row in dtInfo.Rows)                    Trace.WriteLine(row[0]);//调试输出第一列数据                j = dtInfo.Rows.Count;//获取数据库的行数            }            catch (Exception ex)            {                MessageBox.Show(ex.Message);            }        }    }}
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