database_dialect.ts

/*
  Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 
  Licensed under the Apache License, Version 2.0 (the "License").
  You may not use this file except in compliance with the License.
  You may obtain a copy of the License at
 
  http://www.apache.org/licenses/LICENSE-2.0
 
  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
*/

import { HostListProvider } from "../host_list_provider/host_list_provider";
import { ClientWrapper } from "../client_wrapper";
import { FailoverRestriction } from "../plugins/failover/failover_restriction";
import { ErrorHandler } from "../error_handler";
import { TransactionIsolationLevel } from "../utils/transaction_isolation_level";
import { HostRole } from "../host_role";
import { FullServicesContainer } from "../utils/full_services_container";
import { HostInfo } from "../host_info";

export enum DatabaseType {
  MYSQL,
  POSTGRES
}

export interface DatabaseDialect {
  getDefaultPort(): number;
  getHostAliasQuery(): string;
  getHostAliasAndParseResults(targetClient: ClientWrapper): Promise<string>;
  getServerVersionQuery(): string;
  getSetReadOnlyQuery(readOnly: boolean): string;
  getSetAutoCommitQuery(autoCommit: boolean): string;
  getSetTransactionIsolationQuery(level: TransactionIsolationLevel): string;
  getSetCatalogQuery(catalog: string): string;
  getSetSchemaQuery(schema: string): string;
  getDialectUpdateCandidates(): string[];
  getErrorHandler(): ErrorHandler;
  getHostRole(targetClient: ClientWrapper): Promise<HostRole>;
  /**
   * Filters the given hosts down to those reachable from the configured accessible regions.
   *
   * Optional: dialects that are not region-aware (i.e. non-Global Aurora dialects) may omit this
   * method, in which case callers should treat all hosts as available. Implementing this as an
   * optional member avoids breaking out-of-tree custom dialects when the method is introduced.
   */
  filterAvailableHosts?(hosts: HostInfo[], accessibleRegions: string[]): Promise<HostInfo[]>;
  isDialect(targetClient: ClientWrapper): Promise<boolean>;
  getHostListProvider(props: Map<string, any>, originalUrl: string, servicesContainer: FullServicesContainer): HostListProvider;
  isClientValid(targetClient: ClientWrapper): Promise<boolean>;
  getDatabaseType(): DatabaseType;
  getDialectName(): string;
  getFailoverRestrictions(): FailoverRestriction[];
  doesStatementSetReadOnly(statement: string): boolean | undefined;
  doesStatementSetTransactionIsolation(statement: string): TransactionIsolationLevel | undefined;
  doesStatementSetAutoCommit(statement: string): boolean | undefined;
  doesStatementSetSchema(statement: string): string | undefined;
  doesStatementSetCatalog(statement: string): string | undefined;
}