The Database Explorer
The Database Explorer is a graphical interface to
DatabaseLink. It provides a number of useful functions, such as managing connections and working with the data in a database. It can be launched by loading
DatabaseLink and executing the command
DatabaseExplorer.
If you find that the examples in this section do not work as shown, you may need to install or restore the example database with the
DatabaseExamples` package, as described in
"Using the Example Databases".
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On Windows it appears as follows.
At this point you can connect to a database and make queries from its tables. When you have selected the data, it can be used to create a report as a
Mathematica notebook. This will allow you to work with the results in
Mathematica.
This version of the Database Explorer can only select and read data from a database.
The Connection Tool
From the main
Database Explorer window, you can open the
Connection Tool by using the
Connect to a data source button. It can also be launched by executing the command
OpenSQLConnection, described in
Database Connections: Establishing a Connection.
If you do not see the sample databases shown in the picture, you may need to install or restore the example database with the
DatabaseExamples` package, as described in
"Using the Example Databases".
The
Connection Tool shows all of the database connections that appear in configuration files in
DatabaseResources directories. The details of named connections and their configuration files are described in
"Database Resources". From the
Connection Tool you can select a connection and edit or delete it. You can also create a new connection, as described in
"New Connection Wizard".
You can use the
Connect button to open a connection to the database that was selected and update the main
Database Explorer window. You can now make queries from the database.
Querying the Database
When you have connected to a database, as described
previously, the
Database Explorer shows the actual database in the
Connection list and the tables in a scroll list. The following picture shows the result of connecting to the
publisher database. This contains a number of tables. If you select one of the tables, its columns will be shown, and you can select any of them. A button for selecting all the columns is also provided.
Clicking the
Result tab selects the data from the table and selected columns. Here is an example.
The
Query page also has an
Advanced Options button. When you click this button, more options for forming the query are provided. For example, you can put various conditions on columns. Here is an example where data in the TITLE_ID column must be greater than 5000.
Clicking the
Result tab will run the query and display the results.
Saving Queries
When you have set up a query, it can be saved with the
Save the Query button. When you click this button a
Save File dialog box appears that includes a number of locations in
DatabaseResources directories. (
DatabaseResources directories are described in
"Database Resources".) When you launch the
Database Explorer, all the queries that have been saved are made available and can be run.
Exporting to Mathematica
When you have set up a query, the data can be extracted into a report in a
Mathematica notebook document. This can be used for printing or for further work in
Mathematica.To generate a report, click the
Create a notebook button. Here is a sample notebook.
When the data is in
Mathematica, you can process it further with all the tools that
Mathematica provides.
New Connection Wizard
The
New Connection Wizard is available from the
Connection Tool, which can be launched either from the
Database Explorer (described
previously) or by executing the command
OpenSQLConnection[] (described in
"Database Connections: Establishing a Connection"). It will create a new named connection that will be available for future uses. The information about the connection will be written in a configuration file as described in
"Database Resources".
The wizard takes you through the following steps for creating a new connection.
2. Specify name and description.
3. Select type of database.
5. Specify username and password.
A view of the third step is shown in the following picture. In this step, the type of the database is selected from a list. There is also a button for entering a new type of database. The list includes types that have been installed in the system as described in
Database Resources: JDBC Configuration.
Each screen of the wizard has a full description. When it has finished, a new named connection has been created. This can be used by
OpenSQLConnection and will show up in the
Connection Tool.