2.9 KiB
Sample Application
API example code
Here we provide short but complete and working samples of some of the most important parts of the Jones API.
- find.js illustrates using [session.find()] (../../database-jones/API-documentation/Session) to retreive a single record from a table.
- insert.js illustrates using session.persist() to store a record.
- scan.js illustrates using session.createQuery() to build and execute a Query that returns multiple records.
- join.js illustrates using a Projection to define a relationship between tables, and then running session.find() against the projection. The equivalent query in SQL would be a join.
The scan and join samples use the tables in the tweet demo, described below.
The Tweet Demo
This directory contains a Twitter-like demo application using Database Jones.
The SQL script create_tweet_tables.sql contains DDL statements for MySQL to create the five tables used by the demo application. It can be executed using the standard mysql command:
mysql -u root < create_tweet_tables.sql
The Node.js application tweet.js is a rather complete large example which can run as either as a command-line tool or as a REST web server. tweet.js supplements the simple API examples with sample code for explicit transaction handling and batching (e.g. in InsertTweetOperation at line 320). tweet.js responds to a number of verb-object commands; to see a list of them, simply type:
node tweet
Some demonstration scripts are provided to illustrate tweet.js:
- demo_populate_data.sh populates the database with some sample data.
- demo_cli_get.sh demonstrates querying the sample data from the command shell.
- demo_http_get.sh demonstrates querying the sample data (and posting a new tweet) over the HTTP interface.
- demo_http_delete.sh uses the HTTP interface to delete the sample data.
Note that in order to run the HTTP demo scripts, you should first start the server on port 7800, using the command:
node tweet start server 7800
tweet.js pays attention to the environment variables JONES_ADAPTER (which
defaults to "ndb") and JONES_DEPLOYMENT (which defaults to "test").
Connecting to a database server in your environment
Jones applications connect to a particular database using a named deployment defined in the file jones_deployments.js. The sample code uses the "test" deployment. You can customize jones_deployments.js for your environment, and you can supply a different deployment as a command-line option in tweet.js or by editing the call to ConnectionProperties() in the API samples.