architect-oracle-pool

architect-oracle-pool 
=================

Expose a Oracle connection pool as architect plugin. Automaticaly returns connection to the pool after query.

$3

``sh
npm install --save architect-oracle-pool
`

$3


`js
module.exports = [{
packagePath: "architect-oracle-pool",
pools: {
poolName: {
user: 'scott',
password: 'tiger',
connectString: 'backend.local/X3PV7',
poolMax: 10
}
}
}];
`
* pools : Defines the oracle pools configs
* pools.poolName : Defines a oracle pool config to connect a particular database service

$3

Boot Architect :

`js
var path = require('path');
var architect = require("architect");

var configPath = path.join(__dirname, "config.js");
var config = architect.loadConfig(configPath);

architect.createApp(config, function (err, app) {
if (err) {
throw err;
}
console.log("app ready");
});
`

Configure Architect with config.js :

`js
module.exports = [{
packagePath: "architect-oracle-pool",
pools: {
poolName: {
user: 'scott',
password: 'tiger',
connectString: 'backend.local/PV7',
poolMax: 10
}
}
}, './routes'];
`

Consume oradb plugin in your ./routes/package.json :

`js
{
"name": "routes",
"version": "0.0.1",
"main": "index.js",
"private": true,

"plugin": {
"consumes": ["oradb"]
}
}
`
Eventually use Oracle connection in your routes ./routes/index.js :

`js
module.exports = function setup(options, imports, register) {
var rest = imports.rest;
var db = imports.oradb;

// register routes
rest.get('/hello/:name', function (req, res, next) {
db.query('SELECT * FROM Users WHERE id=$1', [req.params.name], function(err, res){
res.write("{'message':'hello," + res.rows[0].name + "'}");
res.end();
});
});

register();
};
`


$3

This module supports multiple pools.

Here is how to define 2 different pools :
`js
module.exports = [{
packagePath: "architect-oracle-pool",
pools: {
first: {
user: 'scott',
password: 'tiger',
connectString: 'backend.local/PV7',
poolMax: 10
},
second : {
user: 'scott',
password: 'tiger',
connectString: 'backend2.local/PV7',
poolMax: 10
}
}
}];
`

This will create 2 properties (first and second) in the db object.
`js
module.exports = function setup(options, imports, register) {
var db = imports.oradb;
db.first.connection(function (err, client) {
client.query(/.../);
});
register();
};
`

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* pools: object with individuals pool config object for pool names
* poolsDrainTime: see drainTime options. Default 10 s. https://node-oracledb.readthedocs.io/en/latest/api_manual/pool.html#pool.close
* pools.poolName: pool config object for an individual pool
* pools.poolName.connectString : the oracle database oracle net services connection string
* pools.poolName.user : username to login,
* pools.poolName.password : password to login

See Oracle createPool




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The pool object (oradb) has the following methods :

#### connection
Retreive a connection from the pool. The method takes a callback as parameter. Once the connection is avaliable the callback is called with an :

* err object if an error occured or null;
* client the Oracle connection object;
* done, the close method.

#### query
The query method let you directly query the database without worrying about the database connection. Behind the scene the method retreive a connection from the pool and close it afterward.
* _string_ text: the query text;
* optional _array_ parameters: the query parameters;
* optional _function_ callback : the function called when data is ready.

Once the data is ready the callback is fired with an :

* err object if an error occured or null;
* rows the result set.

`js
module.exports = function setup(options, imports, register) {
var db = imports.oradb;

db.query('SELECT * from USERS', function (err, res) {
res.rows.forEach(console.log);
});
//...
};
`

#### queryStream
The queryStream method let you directly query the database without worrying about the database connection. This method passes a stream to the callback instead of a resultset.
* _string_ text: the query text;
* optional _array_ parameters: the query parameters;
* optional _function_ callback : the function called when stream is ready.
* returns: ReadableStream

Once the stream is ready the callback is fired with an :

* err object if an error occured or null;
* stream the result stream.

`js
var JSONSteam = require('JSONStream');

module.exports = function setup(options, imports, register) {
var db = imports.oradb;
db.queryStream('SELECT * from USERS')
.pipe(JSONSteam.stringify())
.pipe(process.stdout);
//...
};
``