Part 17: Database crawl

In this article, I will introduce how to crawl and search the data stored in the database.

When retrieving data from a database with SQL, if you want to search under conditions that require linguistic processing, you can use Fess to efficiently search the data in the database. In addition, Fess can crawl and search for any database for which a JDBC driver is provided.

Database settings

This time I will introduce MySQL database crawl as an example. Prepare a MySQL server with the following settings.

item value
url mysql://localhost:3306
Database name testdb
username hoge
password fuga

Also, prepare the following table in testdb.

    title VARCHAR(100) NOT NULL,
    content VARCHAR(255) NOT NULL
    PRIMARY KEY (id)

Enter data in the table as follows.

INSERT INTO doc (title, content) VALUES ('title 1', 'contents 1 ');
INSERT INTO doc (title, content) VALUES ('title 2', 'contents 2 ');
INSERT INTO doc (title, content) VALUES ('title 3', 'contents 3 ');
INSERT INTO doc (title, content) VALUES ('title 4', 'contents 4 ');
INSERT INTO doc (title, content) VALUES ('title 5', 'contents 5 ');

Build Fess

Next, build Fess. This time I will use Fess-13.3.2. You can get the Fess ZIP file from the download page.

JDBC driver installation

After starting Fess, press “Install” in “System in Management Screen”> “Plugins” to display the plugin installation screen. Select “mysql-connector-java-8.0.17” on the remote tab and click “Install” to install the MySQL JDBC driver.


If you want to install one that is not listed, upload the file from the local tab and install it.

Crawl settings

From here, I will explain the setting of MySQL database crawl.

Log in to Fess management screen, and then to New “crawl”> “data store”. Set the following four items on the setting screen.

  • name

  • Handler name

  • The parameter

  • script

Please enter any string in the name. Set the handler name to “DataBaseDataStore”.

This parameter is in accordance with the contents of the database, is set as follows.

sql=select * from doc

Parameter has become a “key = value” format. The explanation of the key is as follows.

Key value
driver Driver class name
url Database server URL
username Username for connecting to the database
password Password to connect to the database
sql SQL statement to get the crawling target

Set the script as follows.

url="http://localhost/" + id
last_modified=new java.util.Date()

Script also has become the same as the parameter “key = value” format. A description of each key is as follows.

Key value
url URL (link to be displayed on the search results)
host hostname
site Site pass
title title
content Document content of the (index target string)
cache Document of cache (not indexed)
digest Digest part displayed in search results
anchor Links included in the document (usually not required)
content_length Document length
last_modified Last updated date of the document

The value is treated as Groovy. Close the string with double quotes. You can use the database column name as a variable.

The value you specify will be indexed for searching, so specify it according to your requirements.