For database migration, I need to convert jpeg image blobs to png blobs. Can this be done pure SQL server way or do I need to have external assemblies to do the conversion?
There is no native SQL Server way to perform this conversion. SQL Server knows nothing of image data and just sees those blobs as a pile of bytes.
You should do this conversion as a separate step after the rest of your conversion and use a tool appropriate for the task. That means a program or script which can query the data, perform the conversion (perhaps using a utility like ImageMagick), then update the data. An even safer option would be to create a new column for the PNG and insert the converted image there, rather than overwriting the JPEG; later, when you're satisfied that no one is using the JPEG any longer, you can drop the column from the table.
Related
I am not sure I am approaching this project correctly. I have a SQL Server database that contains annotation data for images. The annotation data is stored as a blob data type in the database.
First I tried using a SELECT statement to convert the blob to text:
SELECT CONVERT(varchar(max), CONVERT(varbinary(max), blob_column))
FROM table
Then I used an online tool to convert it from HEX to ASCII. I was able to get more data from it. However, most of the converted text is junk. Below is a screenshot viewed in Notepad++.
Is it possible to convert that junk data into something useful? Is there another approach I should try?
Binary Code
0x08000000050000002B000000030000006100640061000A0100002E0200000000000001000000A047EDE73F000000009DE8E73F010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000FFFF0E00000041006300740069006E00690063002000440061006D0061006700650000FFFFFFFFFFFFFFFF00000000000000009858700BEFB01146B269007757A49399000000000000F03F000000000000F03F010000003F000000010000006E00EC000000320200000000FF0001000000A047EDE73F000000009DE8E73F010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000FFFF0B0000004E00650076007500730028004E00650076006900290000FFFFFFFFFFFFFFFF00000000000000002D2C2B3419D5E846AD84FA0BFC98B7A0000000000000F03F000000000000F03F01000000AC0000000400000062006E0065006F00890100002B010000FF00000001000000A047EDE73F000000009DE8E73F010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000FFFF2200000052002F004F0020004E0065006F0070006C00610073006D0020006F006600200075006E006300650072007400610069006E0020006200650068006100760069006F00720000FFFFFFFFFFFFFFFF00000000000000001BC3C234AA150C42A01F6B2086317E8C000000000000F03F000000000000F03F01000000AC0000000400000062006E0065006F009A0100004F010000FF00000001000000A047EDE73F000000009DE8E73F010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000FFFF2200000052002F004F0020004E0065006F0070006C00610073006D0020006F006600200075006E006300650072007400610069006E0020006200650068006100760069006F00720000FFFFFFFFFFFFFFFF0000000000000000308BB8069D17AF4FB539F319E8BE2B13000000000000F03F000000000000F03F01000000150000000200000061003100160100001E010000FF00FF0001000000A047EDE73F000000009DE8E73F010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000010000000000000000000000000000000100000000000000000000000000000001000000000000000000000000000000FFFF090000004D0069006C0064002000410063006E00650000FFFFFFFFFFFFFFFF000000000000000031873239F16ACD48A11A5C0C328705AA000000000000F03F000000000000F03F010000000000000000000000000000000000000000000000
I am trying to import a small table of data from Azure SQL into Snowflake using Azure Data Factory.
Normally I do not have any issues using this approach:
https://learn.microsoft.com/en-us/azure/data-factory/connector-snowflake?tabs=data-factory#staged-copy-to-snowflake
But now I have an issue, with a source table that looks like this:
There is two columns SLA_Processing_start_time and SLA_Processing_end_time that have the datatype TIME
Somehow, while writing the data to the staged area, the data is changed to something like 0:08:00:00.0000000,0:17:00:00.0000000 and that causes for an error like:
Time '0:08:00:00.0000000' is not recognized File
The mapping looks like this:
I have tried adding a TIME_FORMAT property like 'HH24:MI:SS.FF' but that did not help.
Any ideas to why 08:00:00 becomes 0:08:00:00.0000000 and how to avoid it?
Finally, I was able to recreate your case in my environment.
I have the same error, a leading zero appears ahead of time (0: 08:00:00.0000000).
I even grabbed the files it creates on BlobStorage and the zeros are already there.
This activity creates CSV text files without any error handling (double quotes, escape characters etc.).
And on the Snowflake side, it creates a temporary Stage and loads these files.
Unfortunately, it does not clean up after itself and leaves empty directories on BlobStorage. Additionally, you can't use ADLS Gen2. :(
This connector in ADF is not very good, I even had problems to use it for AWS environment, I had to set up a Snowflake account in Azure.
I've tried a few workarounds, and it seems you have two options:
Simple solution:
Change the data type on both sides to DateTime and then transform this attribute on the Snowflake side. If you cannot change the type on the source side, you can just use the "query" option and write SELECT using the CAST / CONVERT function.
Recommended solution:
Use the Copy data activity to insert your data on BlobStorage / ADLS (this activity did it anyway) preferably in the parquet file format and a self-designed structure (Best practices for using Azure Data Lake Storage).
Create a permanent Snowflake Stage for your BlobStorage / ADLS.
Add a Lookup activity and do the loading of data into a table from files there, you can use a regular query or write a stored procedure and call it.
Thanks to this, you will have more control over what is happening and you will build a DataLake solution for your organization.
My own solution is pretty close to the accepted answer, but I still believe that there is a bug in the build-in direct to Snowflake copy feature.
Since I could not figure out, how to control that intermediate blob file, that is created on a direct to Snowflake copy, I ended up writing a plain file into the blob storage, and reading it again, to load into Snowflake
So instead having it all in one step, I manually split it up in two actions
One action that takes the data from the AzureSQL and saves it as a plain text file on the blob storage
And then the second action, that reads the file, and loads it into Snowflake.
This works, and is supposed to be basically the same thing the direct copy to Snowflake does, hence the bug assumption.
I have a table in a SQL Server 2008 with images (JPG) stored in a varbinary column. I was wondering if there's a really simple way of converting a varbinary back to a image file.
For example - I'm using Management Studio, and I am able to just right click on my "cell" with the data in hex format (0xFFD8FFDB0084... etc.) I can paste that sting into a text file. Is there a nice tool to execute on that text file to convert it to a binary file?
Unfortunately, i DO NOT have any EXECUTE permission on this database... (Otherwise I would have been able to use BCP.)
The most convenient method of extracting images from my database was to use a PowerShell script explained here
As mentioned by #SqlACID, simply copying the data from the column i SQL Management Studio would truncate the varbinary to 65K.
I have this:
Create Proc CrearNuevoImagen
#imagen image
AS
INSERT INTO
Imagenes(imagen)
VALUES(
#imagen
)
I see that #imagen is of type 'image'.
My question is save that I have an .jpg image, on my front-end (my asp.net website code), how could I convert the .jpg image to fit into the 'image'-type column? Or does the SQL Server automatically do this for me?
Save your image object to a MemoryStream. Then you can take the byte array out of the memory stream and pass that to SQL Server to save it in your "image" or "varbinary" column.
The image column type is just a binary container; SQL Server doesn't interpret or modify the data you store there at all.
See http://www.informit.com/articles/article.aspx?p=377078
The IMAGE type is just a name for a type that can store a byte array. It is now deprecated and you should use the VARBINARY(MAX) type instead. Saving JPG files into the back end database is actually a bit more complex if you care about performance, because of the need to avoid these relatively large files to be copied into memory. Have a look at Download and Upload images from SQL Server via ASP.Net MVC for an example of efficient streaming of image files stored in SQL Server BLOB fields.
I need to determine file type (i.e., MimeType) of stored data in the SQL Server 2008.
Is there anyway, if possible using SQL query, to identify the content type or MimeType of the binary data stored in the image column?
I think that, if you need that information, it would probably be better to store it in a separate column. Once it's in the DB, your only options really are guessing it from the file name (if you happen to store that) or by detecting the signature from the first few bytes of data.
There is no direct way in SQL Server to do that - there's no metadata on binary columns stored inside SQL Server, unless you've done it yourself.
For SQL Server, a blob is a blob is a blob - it's just a bunch of bytes, and SQL Server knows nothing about it, really. You need to have that information available from other sources, e.g. by storing a file name, file extension, mime type or something else in a separate column.
Marc