fix(redshift): allow standard_conforming_strings option (#10816)

We use sequelize with Redshift using the sequelize postgres dialect. It doesn't support the `standard_conforming_strings` option since it is based on an older version of postgres. Since https://github.com/sequelize/sequelize/commit/850c7fd04669e0fef9238b6dc4f8d6ee93ed71e9 was introduced, sequelize will try to set this option and fail, so I added a config option. 

Co-authored-by: Simon Schick <demwizzy@gmail.com>

lib/dialects/postgres/connection-manager.js

@@ -194,7 +194,7 @@ class ConnectionManager extends AbstractConnectionManager {
     }).tap(connection => {
       let query = '';
 
-      if (connection['standard_conforming_strings'] !== 'on') {
+      if (this.sequelize.options.standardConformingStrings !== false && connection['standard_conforming_strings'] !== 'on') {
         // Disable escape characters in strings
         // see https://github.com/sequelize/sequelize/issues/3545 (security issue)
         // see https://www.postgresql.org/docs/current/static/runtime-config-compatible.html#GUC-STANDARD-CONFORMING-STRINGS

lib/sequelize.js

@@ -70,6 +70,7 @@ class Sequelize {
    * @param {Object}   [options.sync={}] Default options for sequelize.sync
    * @param {string}   [options.timezone='+00:00'] The timezone used when converting a date from the database into a JavaScript date. The timezone is also used to SET TIMEZONE when connecting to the server, to ensure that the result of NOW, CURRENT_TIMESTAMP and other time related functions have in the right timezone. For best cross platform performance use the format +/-HH:MM. Will also accept string versions of timezones used by moment.js (e.g. 'America/Los_Angeles'); this is useful to capture daylight savings time changes.
    * @param {string|boolean} [options.clientMinMessages='warning'] The PostgreSQL `client_min_messages` session parameter. Set to `false` to not override the database's default.
+   * @param {boolean}  [options.standardConformingStrings=true] The PostgreSQL `standard_conforming_strings` session parameter. Set to `false` to not set the option. WARNING: Setting this to false may expose vulnerabilities and is not recommended!
    * @param {Function} [options.logging=console.log] A function that gets executed every time Sequelize would log something.
    * @param {boolean}  [options.benchmark=false] Pass query execution time in milliseconds as second argument to logging function (options.logging).
    * @param {boolean}  [options.omitNull=false] A flag that defines if null values should be passed to SQL queries or not.
@@ -157,6 +158,7 @@ class Sequelize {
       sync: {},
       timezone: '+00:00',
       clientMinMessages: 'warning',
+      standardConformingStrings: true,
       // eslint-disable-next-line no-console
       logging: console.log,
       omitNull: false,

types/lib/sequelize.d.ts

@@ -303,7 +303,16 @@ export interface Options extends Logging {
    *
    * @default all aliases
    */
-  operatorsAliases?: OperatorsAliases | false;
+  operatorsAliases?: OperatorsAliases;
+
+
+  /**
+   * The PostgreSQL `standard_conforming_strings` session parameter. Set to `false` to not set the option.
+   * WARNING: Setting this to false may expose vulnerabilities and is not recommended!
+   *
+   * @default true
+   */
+  standardConformingStrings?: boolean;
 
   /**
    * Sets global permanent hooks.