Database Toolbox

BOOLEAN (MATLAB logical) Data

When you import data of the BOOLEAN type, MATLAB reads the data as a logical data type within the cell array or structure, having a value of 0 (false) or 1 (true). Similarly, you can export logical data from MATLAB to a database. This example illustrates both importing and exporting BOOLEAN data. For more information about the MATLAB logical data type, see Logical Types in the MATLAB Programming documentation.

• Importing BOOLEAN Data
• Exporting BOOLEAN Data

Importing BOOLEAN Data

1. Set Preferences; for this example, set Data return format to cellarray.
2. For the Data operation, choose Select.
3. From Data source, select a data source; for this example, SampleDB.
4. From Tables, select a table; for this example, Products.
5. From Fields, select the fields; for this example, ProductName and Discontinued.
6. Assign the MATLAB workspace variable; for this example, use D.
7. Click Execute to run the query.

1. The VQB retrieves a 77x2 array.

8. Type D in the Command Window and MATLAB displays 77 records, with the first five shown here.

• D = 
      'Chai'                   [0]
      'Chang'                  [0]
      'Aniseed Syrup'          [0]
                [1x28 char]    [0]
                [1x22 char]    [1]
  

9. Compare this to the table in Microsoft Access.

   

   

10. In the VQB Data area, double-click D to view the contents in the Array Editor.

    

11. In the Array Editor, the logical value for the first product, Chai, appears as false instead of 0 for the cell array. This is to distinguish it as a logical value instead of a numeric 0. In the Array Editor, double-click false. Its logical value, 0, appears in a separate window.

    

Exporting Data Using the VQB

Exporting BOOLEAN Data

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