node-query/lib/NodeQuery.js

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"use strict";
let instance = null;
let fs = require('fs'),
helpers = require('./helpers'),
QueryBuilder = require('./QueryBuilder');
/**
* @module NodeQuery
*/
class NodeQuery {
/**
* Constructor
*
* @return {void}
*/
constructor() {
this.instance = null;
}
/**
* Create a query builder object
*
* @memberOf NodeQuery
* @param {String} driverType - The name of the database type, eg. mysql or pg
* @param {Object} connObject - A connection object from the database library you are connecting with
* @param {String} [connLib] - The name of the db connection library you are using, eg. mysql or mysql2. Optional if the same as drivername
* @return {QueryBuilder} - The Query Builder object
*/
init(driverType, connObject, connLib) {
connLib = connLib || driverType;
let paths = {
driver: `${__dirname}/drivers/` + helpers.upperCaseFirst(driverType),
adapter: `${__dirname}/adapters/${connLib}`
};
Object.keys(paths).forEach(type => {
if ( ! fs.existsSync(paths[type]))
{
throw new Error(
`Selected ${type} (` +
helpers.upperCaseFirst(driverType) +
`) does not exist!`
);
}
});
let driver = require(paths.driver);
let $adapter = require(paths.adapter);
let adapter = new $adapter(connObject);
this.instance = new QueryBuilder(driver, adapter);
return this.instance;
}
/**
* Return an existing query builder instance
*
* @return {QueryBuilder} - The Query Builder object
*/
getQuery() {
if ( ! this.instance) {
throw new Error("No Query Builder instance to return");
}
return this.instance;
}
}
module.exports = new NodeQuery();