SQL IMAGE Query

A Binary Large Object (BLOB) is a MySQL data type for binary data like photos, multimedia, and PDF files.

The agent, or handler, of an object is a BLOB. Although the database manager shouldn't need to know what's in the file or how to use it, it can still be included in the database.

This programming method removes the requirement for a distinct image storage file system. Because the data is segregated from the file system, the technique also centralises the database, making it more portable and safe. It's also easier to make backups because you can build a single MySQL dump file that contains all of your data.

When designing applications that require a tightly-coupled database where images must be in sync with relevant data (for example, an employee portal, a student database, or a financial application), images such as students' passport photos and signatures may be stored in a MySQL database alongside other associated information.

You can now stream photos into and out of the database now that the recordset is open. BLOB stands for Binary Large Object and is a data type that refers to an object. The object data type, unlike the character or integer data types, only holds a pointer or reference to the object's value. A BLOB can store a significant amount of data, such as papers, photos, or movies. If you really wanted to, you could put your great American masterpiece in a BLOB (as a file).

MySQL supports four BLOB types:

• TINYBLOB
• BLOB
• MEDIUMBLOB
• LONGBLOB

These are all BLOBs, although the size of each one varies. Because a TINYBLOB is just roughly 256 bytes and a LONGBLOB is 4 terabytes, why would we even make one? The object is the focus of MySQL. Small text files could still be stored in the database rather than having to copy and paste data from the text into some other field. Use the LONGBLOB option in MySQL if you wish to use a BLOB because it supports larger files.

In MySQL BLOB data is saved in a different memory area than the standard table-processing memory in order to conserve memory and processing time.

Binary and varbinary data types can be used to transform from image data types in SQL 2000.

The following steps to convert image as varchar :

create table testimg (id integer, imgdata image)
insert into testimg values (1, cast ('Test row 1' as image))
insert into testimg values (2, cast ('A longer line of test data' as image))
select id, imgdata, cast(cast(imgdata as binary) as varchar(1000)) FROM testing

This'll return a varchar(1000) field containing the text version of what's stored in the field named imgdata.

The LEN() method would allow you to achieve this, but it does not operate on Text, NText, or Image data types, so how do you get the length of a column value.

To return the column's declared length in bytes. To find the length of a column, use the COL LENGTH() method.

The function takes two arguments: the name of the table and the name of the column.

Example 1: Here's an example of utilizing the LEN() function to conduct these instructions on an IMAGE data type:

SELECT name, LEN(packagedata) 
FROM dbo.sysdtspackages;

Here is an example of running these commands on an IMAGE data type using the DATALENGTH() function:

SELECT name, DATALENGTH(packagedata) 
FROM dbo.sysdtspackages;

Example 2: Here’s an example to demonstrate.

USE Music;
SELECT COL_LENGTH('dbo.Artists', 'ArtistName') AS Result;

Output:

Converting image into binary data :-

We can't store an image directly into the database. For this we have two solutions:

To save the image's location in the database Transforming an image to binary data, inserting it into a database, and then changing it back to an image when extracting records.

If we save the location of an image in the database, and that image is deleted or relocated from that place, obtaining the information will be difficult. So it's best to transform a picture to binary data, store it in a database, and then convert it back to an image when retrieving records.

Method to convert an image into binary data :

• FileStream
• MemoryStream

1. FileStream uses file location to convert an image into binary data which we may/may not provide while updating a record.

Filestream enables you to save huge documents, photos, and files directly to the file system. Unlike the BLOB data format, FILESTREAM does not have a storage restriction of up to 2 GB. The underlying file system constraint allows users to keep huge documents. The NTFS streaming API can be used by SQL Server or other programmes to access these files. As a result, we gain from the efficiency of this streaming API while fetching these documents.

In FILESTREAM, we can use the SELECT, INSERT, UPDATE, and DELETE statements in a similar way to a typical database query.

Note: Filestream is not a SQL Server data type for storing information.

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);

Binary data of any length is stored using the IMAGE data type.

IMAGE can store up to 2GB of information. 2,147,483,647 bytes is the maximum length. (Binary Data with Variable Length)

IMAGE is a domain with a LONG BINARY implementation.

Cast/Convert to IMAGE data type is not possible, and vice versa.

Note: The IMAGE function has been deprecated and will be eliminated in a future SQL Server edition. Alternatively, use NVARCHAR(Max).

Syntax :

Notes: IMAGE data type will be removed in future versions of SQL Server, it is recommended to use VARBINARY(max).

Using sql, convert an image field to base64 binary format. Presently, you can decode your photos from their Base64 encoding using a simple SQL Function.

Steps for apply image datatype base64:

• Step 1: Decode and convert Base64-encoded text to binary.
• Step 2: Make a New SSIS Package.
• Step 3: In Integration Services, create a Data Flow Task.
• Step 4: In SSIS, create a Data Source.
• Step 5: Use SQL Server Integration Services to map the columns.
• Step 6: Use Integration Services to export column transformations.

On the internet, there are numerous online programmes for converting an image to a base64 string. One such application is the Online Image To Base64 Converter. Simply upload an image from your computer or provide a URL to an image file on the internet, and the application will generate a base64 encoded text for you.

Example: Here is an example:

CREATE FUNCTION [dbo].[base64_decode] (@base64_text VARCHAR(max)) RETURNS
VARBINARY(max)
    WITH SCHEMABINDING, RETURNS NULL ON NULL INPUT BEGIN
    DECLARE @x XML; SET @x = @base64_text
    RETURN @x.value('(/)[1]', 'VARBINARY(max)') END GO

Example 1: Column 'TvsRecords.FormImage' is invalid in the select list because it is not contained in either an aggregate function or the GROUP BY clause.

You cannot use a fieldname with a aggregate function in select statement without mentioning it in the group by clause. As pointed out by chirag you cannot use an image field in the group by clause.

select count(TvsRecordID),FormImage
from TvsRecords
group by FormImage;

Example 2:

select student.Name,
student.Age,
sum(subject.mark) AS SumOfMarks,

Picture.image -- Picture.image is an image field
from
student inner join subject on student.id = Subject.id
 Left outer join picture on student.id = picture.id
Group by
student.Name,
student.Age,
Picture.image

Using the OPENROWSET command with the BULK and SINGLE_BLOB options is the simplest way to save photos into a table in SQL Server.

Using OPENROWSET to Insert Image Into Table

• First, let’s create a table in SQL Server Management Studio to hold the image file. CREATE TABLE dbo.Images.
• Right-click this dog image and save it to your c:\ drive as “MyImage. png”.
• Now let’s insert the dog image into the database table we created in step 1.

Example 1: First, let me create a new Table to save the photos.

CREATE TABLE SaveFiles
(
    FileID INT IDENTITY(1,1) NOT NULL,
    Name NVARCHAR(50) NOT NULL,
    Files VARBINARY(MAX) NOT NULL
)

Example 2: In this example, we write a Server Query to insert an image into the table using the OPENROWSET:

INSERT INTO [dbo].[SaveFiles] (Name, Files)
SELECT 'Home Page 2', 
BulkColumn FROM OPENROWSET(BULK N'D:\LOGOS\Home Page.png', SINGLE_BLOB) image;

Example 3: Now insert the image into table using the insert into sql. Following is the example of sql:

INSERT INTO pictures VALUES(1, LOAD_FILE('d:\\flower.gif'));

The image data was inserted into the database using MySQL's LOAD_FILE() function.

Just do two separate ALTER TABLEs, since you can only convert image to varbinary(max), but you can, afterwards, change its length:

create table tbl ( 
  id int,
  data image
)
go

insert into tbl(id,data) values
(1,0x0101010101),
(2,0x0204081632)
go

alter table tbl alter column data varbinary(max)
go
alter table tbl alter column data varbinary(200)
go
select * from tbl

Result:

image data in a.txt file with the 0xFFD8FFE000104A structure. I'd like to update an existing image in a table with an Image datatype with the information in my.txt file.

Example 1: The data sets are updated using a standard UPDATE statement, but the modified image is not shown in my application.

update Images set picture=0xFFD8FFE...
where Id=167;

Example 2:

UPDATE YourTable
SET BlobColumn = 
(SELECT  BulkColumn FROM OPENROWSET(BULK  N'C:\YourFile.png', SINGLE_BLOB) AS x)
WHERE ...

Example 3: In the database, I have an Image column. Image is the type of column. I'd like to make some changes. I have such a jpg file for you.

UPDATEt
SETt.Img = s.Img
FROMMyTable AS t
INNER JOINOPENROWSET(BULK N'C:\Image1.jpg', SINGLE_BLOB) AS s(Img)

Main Article :- Sql difference between IMAGE and VARBINARY

Main differences between VARBINARY and BLOB are:

While the 8KB restriction is appropriate for most data formats, it is an issue for most BLOB data. Microsoft built SQL Server to handle BLOB storage differently than it manages storage for other popular data types to fulfill the demands of larger BLOB data.

Example 1:

DECLARE @VarChar VARCHAR(100) = '';
DECLARE @Cnt INT = 1

WHILE @Cnt < 100
BEGIN
          SET @VarChar = @VarChar + 'A'
          SET @Cnt = @Cnt + 1
END
SET @VarChar = @VarChar + 'B'
SELECT @VarChar
SELECT CONVERT(VARCHAR(100),CONVERT(IMAGE, @VarChar));

RESULT:

Explicit conversion from data type image to varchar is not allowed.

VARBINARY(N)

The default length is 1 when N isn't provided in a data definition or variable declaration statement.

The default length is 30 when N is not provided with the CAST function.

Example 2:

DECLARE @VarBinary VARBINARY(MAX);
SET @VarBinary = 123456; 
SET @VarBinary = @VarBinary + 1; 
SELECT CAST(@VarBinary AS INT); 

RESULT:

Example 3: VARBINARY(MAX) data type is used to store images/pdf/word etc files and any data.

store the IMAGE and VARBINARY(MAX) BLOB data types.

CREATE TABLE MyBLOBTable
(blob_id int IDENTITY(1,1),
blob_description varchar(256),
blob_data varbinary(max))

Use the SQL Convert function to convert image data types to clear text and back. The image data type is used to save binary data, and it can hold variable-length binary data ranging from 0 to 231-1 (2,147,483,647) bytes [1].

The big data types IMAGE and (N) TEXT have been phased out in favour of VARBINARY (MAX) and (N) VARCHAR (max).

Although there is an easy ALTER TABLE command to convert current tables, it is unclear what effect this conversion will have. Converting a VARBINARY (max) to an IMAGE resulted in a significant amount of I/O and log use.

Nonetheless, I explored a few types and parameter translation cases. The default setting in IMAGE is to not inline data, while the 'text in row' table option allows you to set a limit on how much data is inlined.

Example 1: The sample below demonstrates how image data can be converted to text:

SELECT CONVERT(char(8), 0x436176656D616E00) AS ‘binary to text’

OUTPUT:

Example 2: The following command produces four tables, two heap tables and two clustered tables, each with various image settings:

DROP TABLE tableHeapWithImageDefault;
DROP TABLE tableHeapWithImageInline;
DROP TABLE tableClusteredWithImageDefault;
DROP TABLE tableClusteredWithImageInline;

CREATE TABLE tableHeapWithImageDefault (cID INT identity(1,1) PRIMARY KEY NOT NULL, cImage IMAGE);
CREATE TABLE tableClusteredWithImageDefault (cID INT identity(1,1) PRIMARY KEY CLUSTERED NOT NULL, cImage IMAGE);

CREATE TABLE tableHeapWithImageInline (cID INT identity(1,1) PRIMARY KEY NOT NULL, cImage IMAGE);
EXEC sp_tableoption 'tableHeapWithImageInline', 'text in row', 'ON';

CREATE TABLE tableClusteredWithImageInline (cID INT identity(1,1) PRIMARY KEY CLUSTERED NOT NULL, cImage IMAGE);
EXEC sp_tableoption 'tableClusteredWithImageInline', 'text in row', 'ON';

Example 3: convert to and text from image field

Working on a Microsoft Dynamics NAV integration, I had a request to be able to insert large text into a blob (picture) field because Dynamic NAV couldn't create large (over 250 characters) text in any other method than a blob field in the version I was connecting to.

It is easy to put text into the field. You just do a cast to image field like this:

declare @longtext varchar(1000)
set @longtext = ‘very long text and so on….’
update tableX set imagetext = cast(@longtext as image)
where id = 1

It's a little more involved to extract the text from the field again, but it's not that difficult if you know how. You must first convert it to varbinary before converting it to varchar. Like this:

select convert(varchar(1000), convert(varbinary(1000),imagetext) from firstdb.dbo.tableX where id = 1;

When I used the above query in the database (like "use firstdb"), the local special characters were returned without any issues. When I conducted the query in the master database (like "use master"), it returned some different characters for the locale special characters. As far as I can tell, the collation in both databases was identical.

Example 1: creating a sample table containing Base64 image data:

CREATE TABLE public.base64image (
id serial PRIMARY KEY,
image_base64 varchar(5000000) NULL);

INSERT INTO base64image
(id,image_base64)
VALUES(1, 'hgf56789');

select * from base64image where id=1

Example 2: base64 will take 33% more storage space, so I want to save it as either as BLOB or as file, but I'm having trouble with these two methods. I am receiving the base64 string from an ajax method from another page, and use $_POST["image"] to get it. my first attempt is to save the image as blob:

$data = $_POST["image"];
$data = str_replace('data:image/png;base64,', '', $data);
$data = str_replace(' ','+',$data);
$data = base64_decode($data);
$sql=mysql_query("INSERT INTO capimages(image)VALUES('$data')");

but if I open the table nothing really got inserted.

If the image is on your MySQL server, you can use the LOAD FILE() command to save it as a BLOB.

Since only a (MAX) data type can be the target in SQL 2000, this statement will fail.

SQL can obtain data from an external provider with the OPENROWSET statement. Bulk is an OPENROWSET service used for entering documents and photos. See BOL "Importing Large Objects Using the OPENROWSET Bulk Rowset Provider" for more information.

Note: We must construct a BLOB column as a type to insert a file or picture into the MySQL table.

The four BLOB types in MySQL are as follows. Each one stores a different quantity of information.

• TINYBLOB
• BLOB
• MEDIUMBLOB
• LONGBLOB

Example 1: Find a small image then execute the following statement:

INSERT INTO BLOBTest
	(BLOBName, BLOBData)

SELECT 'First test file', 
BulkColumn FROM OPENROWSET(
Bulk 'C:\temp\nextup.jpg', SINGLE_BLOB) AS BLOB

Substatute the ‘C:\temp\nextup.jpg’ for the file system path to your file.

Example 2: Using the following table as an example:

CREATE TABLE MyTable (
   image  BLOB
);

-- This will insert a file in a BLOB column.
INSERT INTO MyTable (image) VALUES(LOAD_FILE('/tmp/image.png'));