/**
* Class that wraps database connection libraries
*
* @private
* @param {Promise} instance - The connection object
*/
class Adapter {
/**
* Invoke an adapter
*
* @constructor
* @param {Promise} instance - Promise holding connection object
*/
constructor (instance) {
this.instance = instance;
}
/**
* Run the sql query as a prepared statement
*
* @param {String} sql - The sql with placeholders
* @param {Array} params - The values to insert into the query
* @return {Promise} - returns a promise resolving to the result of the database query
*/
execute (sql, params) {
throw new Error('Correct adapter not defined for query execution');
}
/**
* Transform the adapter's result into a standard format
*
* @param {*} originalResult - the original result object from the driver
* @return {Result} - the new result object
*/
transformResult (originalResult) {
throw new Error('Result transformer method not defined for current adapter');
}
/**
* Close the current database connection
* @return {void}
*/
close () {
this.instance.then(conn => conn.end());
}
}
module.exports = Adapter;
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