Read picture field of db and put in file by datatable

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hello

i have a

picture field

by type

varbinary(MAX)

now i want to read this field by DataTable (no DataReader) and put it to file.

here is code:

System.IO.FileStream File = new System.IO.FileStream("C:\\TempFile\\" + myPictureFileName, System.IO.FileMode.Create, System.IO.FileAccess.Write);
            byte[] bytFile = new byte[File.Length + 1];
            bytFile = (byte[])(Dataset_11.Tables["my_test_table"].Columns["PictureFile"]);  
            File.Write(bytFile, 0, bytFile.Length - 1);
            File.Close();

the line:

bytFile = (byte[])(Dataset_11.Tables["my_test_table"].Columns["PictureFile"]);

is not correct. how should i change this line?
thanks

What I have tried:

i couldn't do anythings for do it.

help

Posted 3-Jan-19 10:24am

Member 13522501

Updated 3-Jan-19 11:54am

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Wendelius · Answer 1 · 2019-01-03T11:55:00

Solution 1

As far as I can see, you only refer to a specific column of a specific DataTable. However, you don't define the row the data is coming from. In order to get the byte data from the data table you should refer to an existing row.

Consider following pseudo example

C#

foreach(DataRow row in Dataset_11.Tables["my_test_table"].Rows) {
   bytedata = row["PictureFile"];
   ...
}

Posted 3-Jan-19 11:55am

Wendelius

Comments

Member 13522501 4-Jan-19 1:29am

thanks. but above code put all picture field. i want only field of current record.

how?

Maciej Los 4-Jan-19 6:26am

What you mean by current record?

Wendelius 4-Jan-19 11:09am

In your post you don't explain what is the current record for you or how it would be selected so based on the information at hand it's impossible to answer.

However, in general you can for example use DataTable.Select Method (System.Data) | Microsoft Docs[^] to fetch a row or a set of rows but as said, without more information it's hard to tell if that is a feasible approach.

Maciej Los 4-Jan-19 6:26am

5ed!

Wendelius 4-Jan-19 11:15am

Thank you!