Saving Queries in Files

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About Generated Files VQB Query Elements in Generated Files

About Generated Files

Select Query > Generate MATLAB File to create a file that contains the equivalent Database Toolbox functions required to run an existing query that was created in VQB. Edit the file to include MATLAB or related toolbox functions, as needed. To run the query, execute the file.

The following is an example of a file generated by VQB:

% Set preferences with setdbprefs.
s.DataReturnFormat = 'cellarray';
s.ErrorHandling = 'store';
s.NullNumberRead = 'NaN';
s.NullNumberWrite = 'NaN';
s.NullStringRead = 'null';
s.NullStringWrite = 'null';
s.JDBCDataSourceFile = '';
s.UseRegistryForSources = 'yes';
s.TempDirForRegistryOutput = '';
setdbprefs(s)

% Make connection to database. Note that the password has been omitted.
% Using ODBC driver.
conn = database('dbtoolboxdemo','','password');

% Read data from database.
e = exec(conn,'SELECT ALL StockNumber,January,February FROM salesVolume');
e = fetch(e);
close(e)

% Close database connection.
close(conn)

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VQB Query Elements in Generated Files

The following VQB query elements do not appear in generated files:

• Generated code files do not include MATLAB workspace variables to which you assigned query results in the VQB query. The file assigns the query results to e; access these results using the variable e.Data. For example, you can add a statement to the file that assigns a variable name to e.Data as follows:

  myVar = e.Data

• For security reasons, generated files do not include passwords required to connect to databases. Instead, the database statement includes the string 'password' as a placeholder. To run files to connect to databases that require passwords, substitute your password for the string password in the database statement.

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Importing and Exporting BOOLEAN Data

Using Database Toolbox Functions

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