Overview of database access

Host On-Demand includes three paths for database access:

• Access through a Host On-Demand display emulation session
  The functionality of the Database On-Demand client is now also integrated into the following types of Host On-Demand display emulation sessions: 3270 Display sessions, 5250 Display sessions, and VT Display sessions. The SQL Wizard and the File Upload Wizard, which were formerly available only in the Database On-Demand client, are now also accessible through these display emulation sessions.

  The following entries are included in the Actions menu of the session window:

  • Actions > Transfer Data > Send Data to Host
    Allows the user to manage and run File Update statements. See Send Data to Host.
  • Actions > Transfer Data > Receive Data from Host
    Allows the user to manage and run SQL statements. See Receive Data from Host.
  • Actions > Data Transfer Defaults
    Allows the user to set Default values for some input fields in the SQL Wizard and the File Upload Wizard. See Data Transfer Defaults.
• Access through macros
  The SQLQuery action allows the macro writer to send an SQL query to a database server, retrieve the data resulting from the query, and then either write the data into a global variable, write the data into a file, or display the data. See SQLQuery action (<sqlquery> element) in the Macro Programming Guide.

  The File Upload action allows the macro writer to send a File Upload command to a database server to create, append data to, replace, or update a host database. See FileUpload action (<fileupload> element) in the Macro Programming Guide.

• Access through the Database On-Demand Applet
  The Database On-Demand applet is available only in the Configuration server-based client model. The applet includes text and graphical interfaces for building and running SQL statements and File Upload statements. See Getting started with Database On-Demand.

With all three paths of database access, users can perform the following actions:

• Connect to a remote database server on a host other than the one to which the session is connected.
  • For example, if a user is running a 3270 Display session that is connected to a zSeries host, the user can also access a remote database server running on an iSeries host.
  • This capability does not apply to the Database On-Demand client, which connects directly to a remote database server.
• Use the SQL Wizard's graphical user interface to build complex SQL statements, or type in or paste SQL statements directly into an input field.
• Build and run the following types of database statements:
  • SQL Select, Insert, Update, and Delete statements.
  • File Upload Create, Replace, Append, and Update statements.
• Retrieve, display, and save the results of SQL Select statements. Results can be saved in the following file formats:
  • ASCII Text (*.txt)
  • Comma-separated values (*.csv)
  • Lotus 1-2-3 (*.wk1)
  • Microsoft Excel - BIFF3 (*.xls)
  • Microsoft Excel - BIFF4 (*.xls)
  • HTML (*.html)
  • XML (*.xml)
• Upload the contents of files in the following file formats:
  • ASCII Text (*.txt)
  • Comma-separated values (*.csv)
  • Lotus 1-2-3 (*.wk1)
  • Microsoft Excel - BIFF3 (*.xls)
  • Microsoft Excel - BIFF4 (*.xls)
  • XML (*.xml)
• Save and reuse SQL statements and File Upload statements.

A Java Database Connectivity (JDBC) driver must be installed on the client workstation. The JDBC driver for an iSeries host (AS/400 Toolbox for Java) is included with Host On-Demand and is automatically downloaded to the client.

If you use a proxy server to connect to an iSeries and you use the Download client, you can decrease the download time when loading the Database On-Demand applet. Edit the CommonJars.js file and replace hoddba.jar with hodpxdba.jar. This smaller jar file contains only the classes needed for running Database On-Demand when connecting through a proxy server.

Example uses of database access

Dynamic queries

Without knowing SQL, a user can use the SQL Wizard to create an SQL statement or to modify an existing SQL statement. The statement can then be executed or saved for later use.

Saved SQL and File Upload statements

Saved SQL and File Upload statements can be distributed to a user or a group of users. The user can then select the saved SQL or File Upload statement and click Run to view the results.

File download

Query results can be saved in various file formats and later imported into a personal productivity program, such as a spreadsheet or a word processor.

File upload

The contents of database files in various formats can be stored into a host database.

Web page publishing

For the Database On-Demand client, results can be written to an HTML template file. An HTML template file is an HTML document that contains special tags indicating where the query results should be imbedded. The resulting Web page contains everything in the template file, including the query results in the specified location.

Security

Applets running under browsers have limited access to system resources, such as local file access and network access. The Host On-Demand client and Database On-Demand client request special permissions from the browser to perform these operations. Browsers display a window asking the user to grant or deny these requests. If the user denies the request, the applet is not granted the privilege, and the operation fails.

Related topics

• Receive Data from Host
• Send Data to Host
• Data Transfer Defaults
• SQLQuery action (<sqlquery> element) Macro Programming Guide
• FileUpload action (<fileupload> element) Macro Programming Guide
• SQL Wizard (Java 1 browsers)
• SQL Wizard (Java 2-enabled browsers)
• File Upload Wizard
• Getting started with Database On-Demand
• Database On-Demand Group/User Options
• Database On-Demand Group/User Statements
• Basic Configuration Steps
• Configuring Host Sessions
• Disable functions
• Disabling functions for end-user clients