UnityJDBC can be downloaded, installed, tested, and configured for your environment in less than 10 minutes. Here are the easy steps:
Downloading - First, download the UnityJDBC package to your computer from http://www.unityjdbc.com/download.php.
Installation - The UnityJDBC installation package
contains the driver, a simple query GUI, and some test programs. The
UnityJDBC_Trial_Install.jar
can be run by typing the command:
java -jar UnityJDBC_Trial_Install.jar
. Follow the prompts to
install UnityJDBC on your machine.
Quick Start - The installation creates a shortcut
to the UnityJDBC SourceBuilder which is a simple graphical query editor and
configuration tool. You can also run it directly using initsources.bat
or initsources.sh
in the installation directory. To try the
sample queries, you will also want to click on the Start Database shortcut or run the
script startDB.bat
or startDB.sh
in the directory
sampleDB/hsqldb
. Below is a screenshot of running a sample query
that joins across two databases.
Writing queries - UnityJDBC uses the standard SQL language. You can include as many databases in the virtual database that you wish. To reference a table in a given database, prefix it with the database name. In the example above, OrderDB.Lineitem refers to the Lineitem table in OrderDB (a user-assigned name for the sample HSQL database), and PartDB.Part refers to the Part table in the PartDB database. Writing queries is as easy as prefixing the table name with the database name!
Creating Your Own Virtual Database - A virtual
database is defined using a sources XML file, often with the default filename of
sources.xml
. Each database also has a schema file storing
information on its tables and fields. These XML files are automatically built by
SourceBuilder, but can also be edited directly at any time. A few quick steps to produce
your own virtual database:
Select File->New Source Group
and use the default
sources.xml
file.
Select File->New Source
and provide the JDBC connection
information for your source. The screenshots below show MySQL and
PostgreSQL.
Write a query that can join across multiple databases. The only difference from standard SQL is that you prefix the table name with the database name.
After creating your virtual database, you will have one
sources.xml
and an XML schema file for each database. These
files can be moved to any location and are used to configure UnityJDBC when using
it with other applications.
Using UnityJDBC - Now that a virtual database is created, there are three general steps to using UnityJDBC common in all cases.
Move the sources.xml
and the XML schema files for the
databases into a desired directory. For this example, the directory is
/unityjdbc
.
Put the unityjdbc.jar
into your
CLASSPATH
as well as the drivers for each database. (Some
drivers are included with the UnityJDBC distribution in the directory
drivers
in the installation folder.) A common
location is in <JAVA_HOME>/jre/lib/ext.
The connection information is the UnityJDBC driver class
unity.jdbc.UnityDriver
and the URL is
jdbc:unity://<relative or absolute path to sources file>
such as jdbc:unity://unityjdbc/sources.xml
.
The UnityJDBC driver can be used with any software that supports JDBC. A screenshot of configuring it in Aqua Data Studio is below. The same connection information applies to all JDBC-based software.
UnityJDBC can also be used with your own Java programs. There is sample code in the
code
directory in the installation folder. Here are two
commands (executed from the code
directory) to compile and run the
sample code:
javac test/ExampleQuery.java
java test.ExampleQuery
If you have issues with compiling or running, try to explicitly indicate the location of the UnityJDBC JAR:
javac -cp .;../unityjdbc.jar;../sampleDB/hsqldb/hsqldb.jar
test/ExampleQuery.java
java -cp .;../unityjdbc.jar;../sampleDB/hsqldb/hsqldb.jar
test.ExampleQuery
To create your own Java program, copy the file
ExampleQuery.java
to MyQuery.java
. There are
2 lines that you must modify. The first line indicates where your new sources XML file
is located on your machine. You may specify an absolute or relative path from the
current directory. The second line you must modify is to change the SQL query to
reference fields and tables in your data source(s). Compile and run the program. Queries
can reference any table or field in any data source in your XML sources file as long as
you prefix a table or field with the database name such as
MyDB.MyTable.MyField
.