KNOWN-PROBLEMS-1.0 |
A list of known problems, bugs, unimplemented features, etc. |
RELEASE-NOTES-1.0 |
The relase notes for DBB V.1.0 |
README-1.0.html |
This file. |
org |
This is the root of the source tree; it contains the Java sources of all classes used by the DBB. |
lib |
This is where the DBB jarfile is, along with other jarfiles. |
gunzip -c dbb-1.0.tar.gz | tar xovf -
This will create the
installation-directory/dbb-1.0
directory and all its subdirectories.
org/eso/ohs/dbb/examples
directory.
You can also try and run the examples as they are distributed -
the DBB distribution packages all you need to compile and run
the example browsers. You'll need access to valid V.1.1.7 Java
runtime environment; please remember to set the JAVA_HOME
environment variable to a correct value, like
/home/javad/jdk1.1.7
In order to run the examples you'll also need to set your
CLASSPATH environment variable as follows:
cd installation-directory/dbb-1.0/lib
setenv CLASSPATH $PWD/dbb.jar:$PWD/jConnect40.jar:$PWD/swingall.jar
cd -
The example browsers connect to the USUPLINUX Sybase server and use some tables in the opc63 database. We set up the guest Sybase account for you to try out the browser: please contact the USS team for the password.
This version of the DBB will print some debugging information on standard output, including the SQL statements generated when initiating a database query.
java org.eso.ohs.dbb.examples.ExampleBrowser0 guest password
where password is the Sybase account password.
This browser allows you to view data in the eso_users
table. Clicking on the Query button will retrieve several
thousand rows; the Count button will tell you how many rows
would be retrieved without actually retrieving them.
While the query is in progress you can interrupt it by clicking on the Break button.
The columns UserID and Name are displayed in
the table. By clicking on the table headers you can sort the
rows you just retrieved (sorting is performed in memory); please
be aware that sorting several thousand rows can require a few
seconds.
The two columns can also be resized and swapped (by stretching
or dragging the column headers); notice however that the next
query will restore the original layout.
To limit the range of rows which are returned you can use the
Name widget in the Selection Criteria
area. Just type a string there, like "Corbel", then
click again on Query. The search string can contain SQL
wildcard characters, like for instance "Cor%"; or
it may contain an SQL operator, like "< Cor" (in
this case, the typed-in operator less than overrides
the default, which is LIKE).
The contents of the Selection Criteria area can be reset by clicking on the Clear button.
You can exit the browser by closing its window, using your window manager's command.
The source file for this browser is
org/eso/ohs/dbb/examples/ExampleBrowser0.java
java org.eso.ohs.dbb.examples.ExampleBrowser1 guest password
In addition to the features offered by the previous example, this
browser offer the possibility of selectively displaying some
columns of the eso_users table, and sort the
result set in a more sophisticated way.
The user can select which columns to retrieve and display by clicking on the Name and E-mail tick boxes in the Selected Columns area. Columns are displayed left-to-right in the order in which they were selected. Note that in this example the UserID column is always retrieved.
The UserID and Name widgets in the Sorting
Criteria area are tri-state buttons.
If nothing is displayed (the default), the
corresponding column is not considered for sorting.
By clicking once on the widget, an upwards triangle is
displayed, and data will sorted be in ascending order
on that column.
A second click will display a downward triangle, which implies
implies sorting in descending order.
One more click will reset the widget to its default state.
When multiple widgets in the Sorting
Criteria area are activated, the sorting conditions are
applied in order of activation.
The setting of the Sorting Criteria affects the way the
SQL query is generated, and therefore the results displayed when
clicking on Query button. However, it also affects the
way the Sort button works, that is to say, how the
in-memory reordering of the result set is performed.
Try sorting a result set with different combinations of the
UserID and Name widgets.
By clicking on the Clear button one can reset the contents of the Selection Criteria, Selected Columns and Sorting Criteria areas.
The source file for this browser is
org/eso/ohs/dbb/examples/ExampleBrowser1.java
To run this example, you must first activate the RMI registry process (this is needed by all Java RMI applications), then the middle-tier server provided with the distribution:
rmiregistry &
java org.eso.ohs.dbb.server.DbbServer \
host 1199 jdbc:sybase:Tds:pclinnt1.hq.eso.org:55500 \
opc63 guest password &
where host is your hostname (for instance
usg1.hq.eso.org) and password is the same as in
the previous examples.
At this point you can start the client, passing the URL of the middle-tier server on the command line:
java org.eso.ohs.dbb.examples.ExampleBrowser2 //host/DBB
where host is again your hostname; so, for instance, a
complete server URL would be: //usg1.hq.eso.org/DBB
To demonstrate how to define joins among tables, this browser
adds a pulldown menu in the Selection Criteria area,
through which the operator can select users belonging to one of
several countries or organizations. This information is kept in
the user_affiliations table; the SQL engine then
builds the join conditions between eso_users and
user_affiliations.
Apart from that, this example browser looks and performs like ExampleBrowser1. Whether you should use a two- or three-tier architecture depends on the application, its security and performance requirements, the available resources, etc.
The source file for this browser is
org/eso/ohs/dbb/examples/ExampleBrowser2.java; for
the distributed DBB server it is
org/eso/ohs/dbb/server/DbbServer.java