Web sql setup using underscore js

web.sql.js

(function () {
    db = {};

    db.map = {
        'jobs': {
            'create': {
                'sql': 'CREATE TABLE "jobs" (id unique, json)'
            },
            'insert': {
                'sql': 'INSERT INTO "jobs" (id, json) VALUES (?,?)'
            },
            'update': {
                'sql': 'UPDATE "jobs" SET json=? WHERE id=?'
            },
            'selectAll': {
                'sql': 'SELECT * FROM  "jobs"'
            },
            'select': {
                'sql': 'SELECT * FROM "jobs" WHERE id=?'
            },
            'remove': {
                'sql': 'DELETE FROM "jobs" WHERE id=?'
            },
            'drop': {
                'sql': 'DROP TABLE "jobs"'
            }
        }
    }

    db.websql = window.websql = function (table, map) {
        this.config = {
            'TABLE': table,
            'MAP' : map || db.map,
            'SETUP': {
                'DB': 'mydb',
                'VERSION': '1.0',
                'DESC': 'database',
                'SIZE': 5 * 1024 * 1024
            }
        }
    }
    _.extend(db.websql.prototype, {
        connection: function () {
            return openDatabase(this.config.SETUP.DB, this.config.SETUP.VERSION, this.config.SETUP.DESC, this.config.SETUP.SIZE)
        },
        map: function (fn) {
            return db.map[this.config.TABLE][fn].sql.toString()
        },
        callback: function (result, options) {
            var _this = this;
            if (typeof (options) !== 'undefined') {
                if (typeof (callback) !== 'undefined') {
                    options.callback.call(_this, result)
                } else {
                    console.log(result)
                }
            } else {
                console.log(result)
            }
        },
        error: function (tx, error) {
            return error.message
        },
        create: function () {
            var _this = this;
            _this.connection().transaction(function (tx) {
                tx.executeSql(_this.map('create'), [], function (tx, result) {
                    _this.callback(result)
                }, _this.Error)
            })
        },
        insert: function (options) {
            var _this = this;
            _this.connection().transaction(function (tx) {
                tx.executeSql(_this.map('insert'), options.values, function (tx, result) {
                    _this.callback(result, options)
                }, _this.Error)
            })
        },
        update: function (options) {
            var _this = this;
            _this.connection().transaction(function (tx) {
                tx.executeSql(_this.map('update'), options.values, function (tx, result) {
                    if (result.rowsAffected > 0) {
                        _this.callback(result, options)
                    } else {
                        _this.insert(options)
                    }
                }, _this.Error)
            })
        },
        selectAll: function (options) {
            var _this = this;
            _this.connection().transaction(function (tx) {
                tx.executeSql(_this.map('selectAll'), [], function (tx, results) {
                    var len = results.rows.length,
                        i, result = [];
                    for (i = 0; i < len; i++) {
                        var row = results.rows.item(i);
                        result.push(row)
                    }
                    _this.callback(result, options)
                }, _this.Error)
            })
        },
        select: function (options) {
            var _this = this;
            _this.connection().transaction(function (tx) {
                tx.executeSql(_this.map('select'), options.values, function (tx, results) {
                    var len = results.rows.length,
                        i, result = [];
                    for (i = 0; i < len; i++) {
                        var row = results.rows.item(i);
                        result.push(row)
                    }
                    _this.callback(result, options)
                }, _this.Error)
            })
        },
        remove: function (options) {
            var _this = this;
            _this.connection().transaction(function (tx) {
                tx.executeSql(_this.map('remove'), options.values, function (tx, result) {
                    _this.callback(result, options)
                }, _this.Error)
            })
        },
        drop: function (options) {
            var _this = this;
            _this.connection().transaction(function (tx) {
                tx.executeSql(_this.map('drop'), [], function (tx, result) {
                    _this.callback(result, options)
                }, _this.Error)
            })
        }
    })
})();