Databases
StackOverflow2013
Postsdbo
PO
 

Note that there are some explanatory texts on larger screens.

plurals
  1. PO
    primarykey
    data
    text
    <p>There is a way that you can do this in chunks so that you don't have to burn a ton of memory all at once.</p> <p>.Net includes an encoder that can do the chunking, but it's in kind of a weird place. They put it in the System.Security.Cryptography namespace.</p> <p>I have tested the example code below, and I get identical output using either my method or Andrew's method above.</p> <p>Here's how it works: You fire up a class called a CryptoStream. This is kind of an adapter that plugs into another stream. You plug a class called CryptoTransform into the CryptoStream (which in turn is attached to your file/memory/network stream) and it performs data transformations on the data while it's being read from or written to the stream. </p> <p>Normally, the transformation is encryption/decryption, but .net includes ToBase64 and FromBase64 transformations as well, so we won't be encrypting, just encoding.</p> <p>Here's the code. I included a (maybe poorly named) implementation of Andrew's suggestion so that you can compare the output.</p> <pre> <code> class Base64Encoder { public void Encode(string inFileName, string outFileName) { System.Security.Cryptography.ICryptoTransform transform = new System.Security.Cryptography.ToBase64Transform(); using(System.IO.FileStream inFile = System.IO.File.OpenRead(inFileName), outFile = System.IO.File.Create(outFileName)) using (System.Security.Cryptography.CryptoStream cryptStream = new System.Security.Cryptography.CryptoStream(outFile, transform, System.Security.Cryptography.CryptoStreamMode.Write)) { // I'm going to use a 4k buffer, tune this as needed byte[] buffer = new byte[4096]; int bytesRead; while ((bytesRead = inFile.Read(buffer, 0, buffer.Length)) > 0) cryptStream.Write(buffer, 0, bytesRead); cryptStream.FlushFinalBlock(); } } public void Decode(string inFileName, string outFileName) { System.Security.Cryptography.ICryptoTransform transform = new System.Security.Cryptography.FromBase64Transform(); using (System.IO.FileStream inFile = System.IO.File.OpenRead(inFileName), outFile = System.IO.File.Create(outFileName)) using (System.Security.Cryptography.CryptoStream cryptStream = new System.Security.Cryptography.CryptoStream(inFile, transform, System.Security.Cryptography.CryptoStreamMode.Read)) { byte[] buffer = new byte[4096]; int bytesRead; while ((bytesRead = cryptStream.Read(buffer, 0, buffer.Length)) > 0) outFile.Write(buffer, 0, bytesRead); outFile.Flush(); } } // this version of Encode pulls everything into memory at once // you can compare the output of my Encode method above to the output of this one // the output should be identical, but the crytostream version // will use way less memory on a large file than this version. public void MemoryEncode(string inFileName, string outFileName) { byte[] bytes = System.IO.File.ReadAllBytes(inFileName); System.IO.File.WriteAllText(outFileName, System.Convert.ToBase64String(bytes)); } } </code> </pre> <p>I am also playing around with where I attach the CryptoStream. In the Encode method,I am attaching it to the output (writing) stream, so when I instance the CryptoStream, I use its Write() method. </p> <p>When I read, I'm attaching it to the input (reading) stream, so I use the read method on the CryptoStream. It doesn't really matter which stream I attach it to. I just have to pass the appropriate Read or Write enumeration member to the CryptoStream's constructor. </p>
    singulars
    1. This table or related slice is empty.
    1. POBase64 Encode a PDF in C#?
      singulars
      1. PTQuestion
    1. PTAnswer
    1. USJMarsch
    1. USJMarsch
    plurals
    1. This table or related slice is empty.
    1. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    3. VO
      singulars
      1. PO
      1. This table or related slice is empty.
      1. VTUpMod
    1. COI haven't ran and verified this, but this looks promisingly good and awesome. Cool idea! +1
      singulars
      1. PO
      1. UScodingbear
    2. COI have tested this. Works like a charm. Nicely done.
      singulars
      1. PO
      1. USmcNux
    3. CO@mcNux: Thanks!
      singulars
      1. PO
      1. USJMarsch
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload