oracle数据库存取图片方法教程

数据库存取图片信息，有两种方式：

1)转换成二进制数据存储，故首先设置对应的数据字段数据类型为Blob.

2)服务器设置路径保存上传文件，数据库中只存储文件路径。

这里采用第一种方式简单示范如何存储并取出图片。涉及几个类的使用，已经做出简单注释。

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Data.OracleClient;//添加引用
namespace ImageDemo
{
    public partial class Form1 : Form
    {
        OpenFileDialog filedialog;
        string connstr = "";
        public Form1()
        {
            connstr = "Data Source=xxx;user id=xxx;password=xxx";
            InitializeComponent();
        }
        /// <summary>
        /// 获得要上传的文件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button2_Click(object sender, EventArgs e)
        {
            filedialog = new OpenFileDialog();
            filedialog.FilterIndex = 1;
            filedialog.Filter = "jpg files (*.jpg)|*.jpg|All files (*.*)|*.*";
            if (filedialog.ShowDialog() == DialogResult.OK)
            {
                txtpath.Text = filedialog.FileName;
            }
        }
        /// <summary>
        /// 上传到数据库中：往数据库存入图片信息
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void button1_Click(object sender, EventArgs e)
        {
            Cursor.Current = Cursors.WaitCursor;
            //获得上传图片的二进制信息
            byte[] buffer = File.ReadAllBytes(txtpath.Text.Trim());
            Random rd = new Random();
            string name = rd.Next(999).ToString();
            string sql = "insert into ivan_qq_user(id,name,image) values('"+Guid.NewGuid().ToString()+"','"+name+"',:image)";
            using (OracleConnection conn = new OracleConnection(connstr))
            {
                conn.Open();
                OracleCommand cmd = new OracleCommand(sql, conn);
                //指名参数类型为Blob
                cmd.Parameters.Add(":image", OracleType.Blob);
                cmd.Parameters[":image"].Value = buffer;
                cmd.ExecuteNonQuery();
            }
            PreviewImage(name);
            Cursor.Current = Cursors.Default;
            MessageBox.Show("Done.....");
        }
        /// <summary>
        /// 预览图像信息：从数据库读图片信息
        /// </summary>
        /// <param name="name"></param>
        private void PreviewImage(string name)
        {
            ISDApp01.ISDApp01 isd = new ImageDemo.ISDApp01.ISDApp01();
            string sql = "select image from IVAN_QQ_USER where name='"+name+"'";
            using (OracleConnection conn = new OracleConnection(connstr))
            {
                conn.Open();
                OracleCommand cmd = new OracleCommand(sql,conn);
                //获得数据信息并转换成二进制
                byte[] fileData = cmd.ExecuteScalar() as byte[];
                MemoryStream ms = new MemoryStream(fileData);
                //把二进制信息转换成image并show出
                Image image = Image.FromStream(ms);
                pictureBox1.Image = image;
            }
        }
    }
}