Objective:
To insert into & retrieve images from SQL server database without using stored procedures and also to perform insert, search, update and delete operations & navigation of records.
Introduction:
As we want to insert images into the database, first we have to create a table in the database, we can use the data type 'image' or 'binary' for storing the image.
Query for creating table in our application:
create table student(sno int primary key,sname varchar(50),course varchar(50),fee money,photo image)
Design:
Design the form as above with 1 PictureBox control, 1 OpenFileDialog control, 4 Labels, 4 TextBoxes and 11 Buttons.
PictureBox1 Properties:
BorderStyle=Fixed3D; SizeMode=StrechImage
Note that OpenFileDialog control appears below the form (not on the form), which can be used for browsing an image.
Introduction to code:
In order to communicate with SQL sever database, include the namespace
'using System.Data.SqlClient'.
In this application, we will search a record by taking input from the InputBox. For this we have to add reference to Microsoft.VisualBasic.
Adding a Reference to 'Microsoft.VisualBasic':
Goto Project Menu ->Add Reference -> select 'Microsoft.VisualBasic' from .NET tab.
In order to use this reference we have to include the namespace:
'using Microsoft.VisualBasic' in the code.
Converting image into binary data:
We can't store an image directly into the database. For this we have two solutions:
- To store the location of the image in the database
- Converting the image into binary data and insert that binary data into database and convert that back to image while retrieving the records.
If we store the location of an image in the database, and suppose if that image is deleted or moved from that location, we will face problems while retrieving the records. So it is better to convert image into binary data and insert that binary data into database and convert that back to image while retrieving records.
We can convert an image into binary data using
- FileStream
- MemoryStream
1. FileStream uses file location to convert an image into binary data which we may/may not provide while updating a record.
Example:
FileStream fs = new FileStream(openFileDialog1.FileName, FileMode.Open, FileAccess.Read);
byte[] photo_aray = new byte[fs.Length];
fs.Read(photo_aray, 0, photo_aray.Length);
2. So it is better to use MemoryStream which uses image in the PictureBox to convert an image into binary data.
Example:
MemoryStream ms = new MemoryStream();
pictureBox1.Image.Save(ms, ImageFormat.Jpeg);
byte[] photo_aray = new byte[ms.Length];
ms.Position = 0;
ms.Read(photo_aray, 0, photo_aray.Length);
In order to use FileStream or MemoryStream we have to include the namespace:
'using System.IO'.
OpenFileDialog Control:
We use OpenFileDialog control in order to browse for the images (photos) to insert into the record.
Loading the constraint details into the dataTable:
In this app. we use Find() method to search a record, which requires details of primarykey column, which can be provided using the statement:
adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
Pointing to current record in dataTable:
After searching a record, we have to get the index of that record so that we can navigate the next and previous records.
Example:
rno= ds.Tables[0].Rows.IndexOf(drow);
-------------
Code:
using System;
using System.Windows.Forms;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using Microsoft.VisualBasic;
namespace inserting_imgs
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
SqlConnection con;
SqlCommand cmd;
SqlDataAdapter adapter;
DataSet ds; int rno = 0;
MemoryStream ms;
byte[] photo_aray;
private void Form1_Load(object sender, EventArgs e)
{
con = new SqlConnection("user id=sa;password=123;database=prash");
loaddata();
showdata();
}
void loaddata()
{
adapter = new SqlDataAdapter("select sno,sname,course,fee,photo from student", con);
adapter.MissingSchemaAction = MissingSchemaAction.AddWithKey;
ds = new DataSet(); adapter.Fill(ds, "student");
}
void showdata()
{
if (ds.Tables[0].Rows.Count > 0)
{
textBox1.Text = ds.Tables[0].Rows[rno][0].ToString();
textBox2.Text = ds.Tables[0].Rows[rno][1].ToString();
textBox3.Text = ds.Tables[0].Rows[rno][2].ToString();
textBox4.Text = ds.Tables[0].Rows[rno][3].ToString();
pictureBox1.Image = null;
if (ds.Tables[0].Rows[rno][4] != System.DBNull.Value)
{
photo_aray = (byte[])ds.Tables[0].Rows[rno][4];
MemoryStream ms = new MemoryStream(photo_aray);
pictureBox1.Image = Image.FromStream(ms);
}
}
else
MessageBox.Show("No Records");
}
private void browse_Click(object sender, EventArgs e)
{
openFileDialog1.Filter = "jpeg|*.jpg|bmp|*.bmp|all files|*.*";
DialogResult res = openFileDialog1.ShowDialog();
if (res == DialogResult.OK)
{
pictureBox1.Image = Image.FromFile(openFileDialog1.FileName);
}
}
private void newbtn_Click(object sender, EventArgs e)
{
cmd = new SqlCommand("select max(sno)+10 from student", con);
con.Open();
textBox1.Text = cmd.ExecuteScalar().ToString();
con.Close();
textBox2.Text = textBox3.Text = textBox4.Text = "";
pictureBox1.Image = null;
}
private void insert_Click(object sender, EventArgs e)
{
cmd = new SqlCommand("insert into student(sno,sname,course,fee,photo) values(" + textBox1.Text + ",'" +
textBox2.TabIndex + "','" + textBox3.Text + "'," + textBox4.Text + ",@photo)", con);
conv_photo();
con.Open();
int n = cmd.ExecuteNonQuery();
con.Close();
if (n > 0)
{
MessageBox.Show("record inserted");
loaddata();
}
else
MessageBox.Show("insertion failed");
}
void conv_photo()
{
//converting photo to binary data
if (pictureBox1.Image != null)
{
//using FileStream:(will not work while updating, if image is not changed)
//FileStream fs = new FileStream(openFileDialog1.FileName, FileMode.Open, FileAccess.Read);
//byte[] photo_aray = new byte[fs.Length];
//fs.Read(photo_aray, 0, photo_aray.Length);
//using MemoryStream:
ms = new MemoryStream();
pictureBox1.Image.Save(ms, ImageFormat.Jpeg);
byte[] photo_aray = new byte[ms.Length];
ms.Position = 0;
ms.Read(photo_aray, 0, photo_aray.Length);
cmd.Parameters.AddWithValue("@photo", photo_aray);
}
}
private void search_Click(object sender, EventArgs e)
{
try
{
int n = Convert.ToInt32(Interaction.InputBox("Enter sno:", "Search", "20", 100, 100));
DataRow drow;
drow = ds.Tables[0].Rows.Find(n);
if (drow != null)
{
rno = ds.Tables[0].Rows.IndexOf(drow);
textBox1.Text = drow[0].ToString();
textBox2.Text = drow[1].ToString();
textBox3.Text = drow[2].ToString();
textBox4.Text = drow[3].ToString();
pictureBox1.Image = null;
if (drow[4] != System.DBNull.Value)
{
photo_aray = (byte[])drow[4];
MemoryStream ms = new MemoryStream(photo_aray);
pictureBox1.Image = Image.FromStream(ms);
}
}
else
MessageBox.Show("Record Not Found");
}
catch
{
MessageBox.Show("Invalid Input");
}
}
private void update_Click(object sender, EventArgs e)
{
cmd = new SqlCommand("update student set sname='" + textBox2.Text + "', course='" + textBox3.Text + "', fee='" + textBox4.Text + "', photo=@photo where sno=" + textBox1.Text, con);
conv_photo();
con.Open();
int n = cmd.ExecuteNonQuery();
con.Close();
if (n > 0)
{
MessageBox.Show("Record Updated");
loaddata();
}
else
MessageBox.Show("Updation Failed");
}
private void delete_Click(object sender, EventArgs e)
{
cmd = new SqlCommand("delete from student where sno=" + textBox1.Text, con);
con.Open();
int n = cmd.ExecuteNonQuery();
con.Close();
if (n > 0)
{
MessageBox.Show("Record Deleted");
loaddata();
rno = 0;
showdata();
}
else
MessageBox.Show("Deletion Failed");
}
private void first_Click(object sender, EventArgs e)
{
rno = 0; showdata();
MessageBox.Show("First record");
}
private void previous_Click(object sender, EventArgs e)
{
if (rno > 0)
{
rno--; showdata();
}
else
MessageBox.Show("First record");
}
private void next_Click(object sender, EventArgs e)
{
if (rno < ds.Tables[0].Rows.Count - 1)
{
rno++; showdata();
}
else
MessageBox.Show("Last record");
}
private void last_Click(object sender, EventArgs e)
{
rno = ds.Tables[0].Rows.Count - 1;
showdata(); MessageBox.Show("Last record");
}
private void exit_Click(object sender, EventArgs e)
{
this.Close();
}
}
}