Add proxy class to node-mysql

src/Mysql.js

@@ -0,0 +1,162 @@
+/**
+ * Proxy class to node-mysql
+ * Provides some convenient methods for simple queries
+ *
+ * @author: EgorKluch ([email protected])
+ * @date: 29.12.13
+ */
+
+var mysql = require('mysql');
+var config = require('../config/config');
+
+var Mysql = function (callback) {
+  if (Mysql.instance) {
+    return Mysql.instance;
+  }
+  Mysql.instance = this;
+
+  this.connection = mysql.createConnection(config.mysql);
+  this.connection.connect(function(err) {
+    if (err) throw err;
+    if (callback) callback(this);
+  }.bind(this));
+
+  return this;
+};
+
+/**
+ * Select rows from {table} who match {where}
+ * In result row inludes only {columns} fields
+ *
+ * @param table
+ * @param columns
+ * @param where
+ * @param callback
+ */
+Mysql.prototype.select = function (table, columns, where, callback) {
+  table = mysql.escapeId(table);
+  if (where) {
+    where = ' where ' + this._getWhereString(where);
+  }
+
+  if (columns === null) {
+    columns = '*'
+  } else {
+    columns = columns.forEach(function (column) {
+      return mysql.escapeId(column);
+    }).join(', ');
+  }
+
+  var query = 'select ' + columns + ' from ' + table + where;
+  this.query(query, callback);
+};
+
+/**
+ * Return first result of this.select method result
+ *
+ * @param table
+ * @param columns
+ * @param where
+ * @param callback
+ */
+Mysql.prototype.one = function (table, columns, where, callback) {
+  this.select(table, columns, where, function (rows) {
+    callback(rows[0]);
+  });
+};
+
+/**
+ * Insert row into {table}
+ *
+ * @param table
+ * @param fields
+ * @param callback
+ */
+Mysql.prototype.insert = function (table, fields, callback) {
+  var query = 'insert into' + mysql.escapeId(table);
+  query += '(' + Object.keys(fields).forEach(function (field) {
+    return mysql.escapeId(field);
+  }).join(', ') + ')';
+  query += ' values(' + Object.values(fields).forEach(function (value) {
+    return mysql.escape(value);
+  });
+  this.query(query, callback);
+};
+
+/**
+ * Update {table} from {values} source for rows, who match {where}
+ *
+ * @param table
+ * @param where
+ * @param values
+ */
+Mysql.prototype.update = function (table, where, values) {
+  var query = 'update ' + mysql.escapeId(table);
+  query += ' set ' + this._getWhereString(values, ',');
+  query += ' where ' + this._getWhereString(where);
+  this.query(query, callback)
+};
+
+/**
+ * Delete rows from {table} who match {where}
+ *
+ * @param table
+ * @param where
+ */
+Mysql.prototype.delete = function (table, where) {
+  var query = 'delete from ' + mysql.escapeId(table);
+  query += ' where ' + this._getWhereString(where);
+  this.query(query, callback);
+};
+
+/**
+ * Execute query
+ * Data define source for escaping query values:
+ *    https://github.com/felixge/node-mysql#escaping-query-values
+ *
+ * Two different call:
+ *  - this.query(query, data, callback)
+ *  - this.query(query, callback)
+ *
+ * Return result rows in {callback}
+ *
+ * @param query
+ * @param data
+ * @param callback
+ */
+Mysql.prototype.query = function (query, data, callback) {
+  if (arguments.length === 2) {
+    callback = data;
+    data = [];
+  }
+  this.connection.query(query, data, function (err, rows) {
+    if (err) throw err;
+    callback(rows);
+  });
+};
+
+/**
+ * Build where string from where object
+ * Example: { a:1, b:2, or: { c: 3, and: { d:4, e:5 } } } transform to
+ *    a=1 and b=2 and (c=3 or (d=4 and e=5))
+ *
+ * @param where
+ * @param operator
+ * @returns {*}
+ * @private
+ */
+Mysql.prototype._getWhereString = function (where, operator) {
+  if (where === null) return '';
+  if (_.isString(where)) return where;
+
+  if (!operator) operator = 'and';
+
+  return _.forEach(where, function (field, value) {
+    if (field === 'and' || field === 'or') {
+      return ' (' + this._getWhereString(value, field)  + ')';
+    }
+    return mysql.escapeId(field) + '=' + mysql.escape(value);
+  }.bind(this)).join(' ' + operator + ' ');
+};
+
+exports = Mysql;