JavaScript Environments

create or replace MLE module module_one
language javascript as

// this function is exported and will be called by
// module_2's greeting() function
export function hello(who) {

    return 'hello ' + who;
}
/

create or replace MLE module module_two
language javascript as

// before module_1's hello() function can be imported a
// so-called import name must be defined by means of creating
// a JavaScript environment. The module name does not have to
// match the import name
import { hello } from 'module1'

export function greeting() {

    const who = 'JavaScript';
    return hello(who);
}
/

// the mapping between import name and module name is defined
// in an environment
create or replace mle env example_env
imports (
    'module1' module module_one
);

// with the module in place it is possible to invoke module_2's
// greeting function. Refer to the section about call specifications
// for more details about invoking JavaScript code in SQL and PL/SQL
create or replace function f_greeting
return varchar2 as
mle module module_two
env example_env
signature 'greeting';
/

select
    f_greeting;

SQL> create or replace MLE module module_one
  2  language javascript as
  3
  4  // this function is exported and will be called by
  5  // module_2's greeting() function
  6  export function hello(who) {
  7
  8      return 'hello ' + who;
  9  }
 10  /

MLE module created.

SQL> create or replace MLE module module_two
  2  language javascript as
  3
  4  // before module_1's hello() function can be imported a
  5  // so-called import name must be defined by means of creating
  6  // a JavaScript environment. The module name does not have to
  7  // match the import name
  8  import { hello } from 'module1'
  9
 10  export function greeting() {
 11
 12      const who = 'JavaScript';
 13      return hello(who);
 14  }
 15  /

MLE module created.

SQL> -- the mapping between import name and module name is defined
SQL> -- in an environment
SQL> create or replace mle env example_env
  2  imports (
  3      'module1' module module_one
  4  );

MLE env created.

SQL> -- with the module in place it is possible to invoke module_2's
SQL> -- greeting function. Refer to the section about call specifications
SQL> -- for more details about invoking JavaScript code in SQL and PL/SQL
SQL> create or replace function f_greeting
  2  return varchar2 as
  3  mle module module_two
  4  env example_env
  5  signature 'greeting';
  6  /

Function created.

SQL> -- call the function
SQL> select
  2      f_greeting;

F_GREETING
-------------------------------------------------------------------------------
hello JavaScript