The document discusses the integration of PL/SQL and JavaScript using Oracle's Multilingual Engine (MLE) available in Oracle 21c and APEX 20.2. It highlights the capabilities of the dbms_mle PL/SQL package to execute JavaScript code within the database, demonstrating code examples for various operations such as executing DML and validations. The author, Rodrigo Mesquita, is a senior Oracle developer with extensive experience, detailing the process of creating and managing contexts for JavaScript execution.

1. It's Time to Get Ready for the Power
of PL/SQL and JavaScript Combined
Rodrigo Mesquita
March 30th, 2023

2. About Rodrigo
• Senior Oracle Developer at QV Systems - UK leading software
provider of asset back finance such as Auto Finance.
• 20 years of Oracle Experience
• Oracle ACE Pro
• UKOUG - 2018 Best New UK Speaker
• Twitter: @mesquitarod

3. apexblog.dev

4. The Multilingual Engine (MLE)
• Available from Oracle 21c and APEX 20.2
• Oracle Database provides the DBMS_MLE PL/SQL package to evaluate
JavaScript code within a database session
• Powered by GraalVM Multilingual Engine: Javascript could be just the
beginning.

5. apex.server.process
Client Side Server Side
Javascript PL/SQL
Oracle Database
with APEX

6. MLE
Client Side Server Side
PL/SQL & Javascript
Oracle Database
with APEX
and MLE

7. MLE with APEX
• Processes
• Computations
• Validation
• Execute Server-side Code dynamic action
• SQL Commands
• Region Source

8. MLE
Non-MLE
Page
Submit
PL/SQL
JavaScript
PL/SQL
JavaScript
PL/SQL
JavaScript
PL/SQL
Before After

9. apex.env - allow us to interact with page items
apex.conn.execute - execute DML or PL/SQL
JavaScript as a Server-Side Language in Oracle APEX by Stephan Dobre

10. DECLARE
ctx dbms_mle.context_handle_t;
user_code clob := q'~
console.log('Hello World!');
~';
BEGIN
ctx := dbms_mle.create_context();
dbms_mle.eval(ctx, 'JAVASCRIPT', user_code);
dbms_mle.drop_context(ctx);
EXCEPTION
WHEN others THEN
dbms_mle.drop_context(ctx);
RAISE;
END;

11. DECLARE
ctx dbms_mle.context_handle_t;
result varchar2(100);
user_code clob := q'~
let bindings = require('mle-js-bindings');
let val = bindings.importValue('value');
bindings.exportValue('response', val+' is awesome');
~';
BEGIN
ctx := dbms_mle.create_context();
dbms_mle.export_to_mle(ctx, 'value', 'APEX');
dbms_mle.eval(ctx, 'JAVASCRIPT', user_code);
dbms_mle.import_from_mle(ctx, 'response', result);
dbms_mle.drop_context(ctx);
dbms_output.put_line(result);
EXCEPTION
WHEN others THEN
dbms_mle.drop_context(ctx);
RAISE;
END;
/

12. DECLARE
ctx dbms_mle.context_handle_t;
result varchar2(100);
user_code clob := q'~
let bindings = require('mle-js-bindings');
const oracledb = require('mle-js-oracledb');
const conn = oracledb.defaultConnection();
let val = bindings.importValue('value');
const code = "update customers set full_name = 'Rodrigo Mesquita' where customer_id = "+val;
conn.execute(code);
~';
BEGIN
ctx := dbms_mle.create_context();
dbms_mle.export_to_mle(ctx, 'value', 1);
dbms_mle.eval(ctx, 'JAVASCRIPT', user_code);
dbms_mle.drop_context(ctx);
EXCEPTION
WHEN others THEN
dbms_mle.drop_context(ctx);
RAISE;
END;

13. DECLARE
ctx DBMS_MLE.context_handle_t := DBMS_MLE.create_context();
user_code clob := q'~
const oracledb = require('mle-js-oracledb');
const OracleNumber = require('mle-js-plsqltypes').OracleClob;
let bindings = require('mle-js-bindings');
const conn = oracledb.defaultConnection();
let val = bindings.importValue('value');
const query = "SELECT full_name AS name FROM customers where customer_id = "+val;
const options = { fetchInfo: { name: { type: oracledb.ORACLE_CLOB } } };
const result = conn.execute(query, [], options);
console.log(result.rows[0][0]);
~';
BEGIN
DBMS_MLE.export_to_mle(ctx, 'value', 1);
DBMS_MLE.eval(ctx, 'JAVASCRIPT', user_code);
DBMS_MLE.drop_context(ctx);
EXCEPTION
WHEN others THEN
DBMS_MLE.drop_context(ctx);
RAISE;
END;

14. API USER
CLIENT SECRET
STRING =
API User +
Client Secret +
timestamp

15. Automation DB Procedure