Serialize and Work with a Document in a Database
One of the tasks you may need to get done when working with documents is storing and retrieving Document objects to and from a database. For example, this would be necessary if you were implementing any type of content management system. All previous versions of documents must be stored in the database system. The ability to store documents in the database is also extremely useful when your application provides a web-based service.
Aspose.Words provides an ability to convert a document into a byte array for subsequent work with this document in a database.
Convert a Document to Byte Array
To store a document in a database or to prepare a document for transmission across the web, it is often necessary to serialize the document to obtain a byte array.
To serialize a Document object in Aspose.Words:
- Save it to a MemoryStream using the Save method overload of the Document class.
- Call the ToArray method, which returns an array of bytes representing the document in byte form.
The steps above then can be reversed to load the bytes back into a Document object.
The example below shows how to serialize a Document object to obtain a byte array, and then how to unserialize the byte array to obtain a Document object again:
Store, Read and Delete a Document in a Database
This section shows how to save a document in a database and then load it back into a Document object for working with it. For simplicity, the file name is the key used to store and fetch documents from the database. The database contains two columns. The first column “FileName” is stored as a String and is used to identify documents. The second column “FileContent” is stored as a BLOB object which stores the document object in the byte form.
The following code example shows how to set up a connection to a database and execute commands:
The following code example shows how to save a document to the database, then read the same document again, and finally delete the record containing the document from the database:
Save a Document to a Database
To save a document in a database convert this document to an array of bytes, as described at the beginning of this article. Then, save this byte array into a database field.
The following code example shows how to save a document to the specified database:
Specify commandString, which is an SQL expression that does all the work:
- To save a document into the database, the “INSERT INTO” command is used and a table specified along with the values of two record fields – FileName and FileContent. To avoid additional parameters, the file name is taken from the Document object itself. The FileContent field value is assigned bytes from the memory stream, which contains a binary representation of the stored document.
- The remaining line of code executes the command which stores the Aspose.Words document in the database.
Retrieve a Document from a Database
To retrieve a document from the database, select the record that contains the document data as an array of bytes. Then load the byte array from the record into MemoryStream and create a Document object that will load the document from the MemoryStream.
The following code example shows how to retrieve and return a document from the specified database using the filename as a key to fetch this document:
Delete a Document from a Database
To delete a document from the database, use the appropriate SQL command without any manipulations on the Document object.
The following code example shows how to delete a document from the database, using the file name to fetch the record: