Database Toolbox™

Retrieving BINARY or OTHER Sun Java SQL Data Types

This example retrieves images from the SampleDB data source using a sample file that parses image data, matlabroot/toolbox/database/vqb/parsebinary.m.

1. Connect to the SampleDB data source.

   conn = database('SampleDB', '', '');
   

2. Specify cellarray as the data return format preference.

   setdbprefs('DataReturnFormat','cellarray');
   

3. Import the EmployeeID and Photo columns of data from the Employees table.

   curs = exec(conn, 'select EmployeeID,Photo from Employees')
   curs = fetch(curs);
   

4. View the data you imported.

   curs.Data
   ans = 
   
       [1]    [21626x1 int8]
       [2]    [21626x1 int8]
       [3]    [21722x1 int8]
       [4]    [21626x1 int8]
       [5]    [21626x1 int8]
       [6]    [21626x1 int8]
       [7]    [21626x1 int8]
       [8]    [21626x1 int8]
       [9]    [21626x1 int8]

   Note   Some OTHER data type fields may be empty, indicating that the data could not pass through the JDBC/ODBC bridge.

5. Assign the image element you want to the variable photo.

   photo = curs.Data{1,2};
   

6. Run parsebinary. This program writes the retrieved data to a file, strips ODBC header information from it, and displays photo as a bitmap image in a figure window. Ensure that your current directory is writable so that the output of parsebinary can be written to it.

   cd 'I:\MATLABFiles\myfiles
   parsebinary(photo, 'BMP');
   

   For more information on parsebinary, enter help parsebinary or view the M-file in the MATLAB Editor/Debugger by entering open parsebinary.

Exporting Multiple Records from the MATLAB Workspace

Working with Database Metadata