This document discusses how to use databases in Jolie by connecting to a sample database called MyDB containing a table called People. It explains how to prepare the JDBC driver library, include the database.iol library, configure the connection, create queries to read and write data, and get the query results. Operations covered include connect, query, update, and getting row data. The goal is to develop a Jolie service that can interact with the database.

1. Using databases in Jolie
http://www.jolie-lang.org
Copyright © 2014 The Jolie Team.
This work is licensed under the Creative Commons Attribution License (CC BY).
To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0

2. Let's suppose you have a Database
The name of your Database is MyDB and it
contains one table called People
id name surname
1 John Smith
2 Donald Duck
You want to develop a Jolie service able to read
and to write from/into MyDB

3. Prepare libraries
Jolie connects databases through JDBC drivers.
Prepare the JDBC .jar library of your database
server as it follows:
lib
yourJDBCdriver.jar
your_service.ol
1) Create a folder named lib in the same path where
your jolie service is
2) Put the JDBC .jar driver into the folder lib

4. Adding database.iol
First of all, add Database.iol into your service
include “database.iol”

5. Create the connection
Configure connection and
use connect operation
with( connectionInfo ) {
.host = “127.0.0.1”;
.driver = “drivername”; //ex: postgresql
.port = 5432;
.database = “MyDB”;
.username = “myusername”;
.password = “mypassword”
};
connect@Database( connectionInfo )()

6. Create a query
Jolie is equipped with protection against SQL
injection. You can pass parameters to the query.
q = “select name from people where id>:id”;
q.id = 0;
Parameters in SQL queries
are prefixed with “:”
Parameters values are
passed as message fields
query@Database( q )( result );

7. Get the result
Rows are listed in subvector row where
subfields are column.
result
.row[0]
.name = “John”
.surname = “Smith”
.row[1]
.name = “Donald”
.surname = “Duck”

8. Update the table
Update a table it is easy, use update
operation instead of query.
q = “insert into people (name,surname)
values (:name,:surname)”;
q.name = “Homer”;
q.surname = “Simpsons”;
update@Database( q )( result )

9. The first language for
microservices
http://www.jolie-lang.org
Copyright © 2014 The Jolie Team.
This work is licensed under the Creative Commons Attribution License (CC BY).
To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0

10. The first language for
microservices
http://www.jolie-lang.org
Copyright © 2014 The Jolie Team.
This work is licensed under the Creative Commons Attribution License (CC BY).
To view a copy of this license, visit https://creativecommons.org/licenses/by/4.0