317brian commented on code in PR #13343: URL: https://github.com/apache/druid/pull/13343#discussion_r1019410172
########## docs/tutorials/tutorial-jdbc.md: ########## @@ -0,0 +1,130 @@ +--- +id: tutorial-jdbc +title: "Tutorial: Using the JDBC driver to query Druid" +--- + +<!-- + ~ Licensed to the Apache Software Foundation (ASF) under one + ~ or more contributor license agreements. See the NOTICE file + ~ distributed with this work for additional information + ~ regarding copyright ownership. The ASF licenses this file + ~ to you 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. + --> + +Learn to connect to your Druid instance using the [Avatica JDBC driver](https://calcite.apache.org/avatica/downloads/) to make Druid SQL queries. You can run queries that return metadata about a datasource or run queries against a datasource. + +For more information about the JDBC driver, see [SQL JDBC driver API](../querying/sql-jdbc). + +## Before you start + +Make sure you meet the following requirements before starting the tutorial: + +- A supported Java version, such as Java 8 + +- [Avatica JDBC driver](https://calcite.apache.org/avatica/downloads/). You can add the JAR to your `CLASSPATH` directly or manage it externally, such as through Maven and a `pom.xml` file. + +- An available Druid instance. You can use the `micro-quickstart` configuration described in [Quickstart (local)](./index.md). The tutorials assume that you are using the quickstart, so no authentication or authorization is expected unless explicitly mentioned. + +- The example `wikipedia` datasource from the quickstart is loaded on your Druid instance. If you have a different datasource loaded, you can still try this tutorial. You'll have to update the table name and column names to match your datasource. + +Keep the following in mind when trying these the Java examples: +- The `url` variable includes the following: + - `jdbc:avatica:remote:url=` prepended to the hostname and port + - the hostname and port. In the case of the quickstart deployment, `http:localhost:8888`. + - the SQL endpoint in Druid for the Avatica driver, `/druid/v2/sql/avatica/` + - For more information about the connection options, see [Client Reference](https://calcite.apache.org/avatica/docs/client_reference.html). +- The `query` variable contains the SQL query you want to submit to Druid. + +## Get the metadata for a datasource + +Metadata, such as column names, is available either through the [`INFORMATION_SCHEMA`](../querying/sql-metadata-tables.md) table or through `connect.getMetaData()`. The following example uses the `INFORMATION_SCHEMA` table to retrieve and print the list of column names for the `wikipedia` datasource that you loaded during a previous tutorial. + +```java +import java.sql.*; +import java.util.Properties; + +public class JdbcListColumns { + + public static void main(String args[]) throws SQLException + { + // Connect to /druid/v2/sql/avatica/ on your Broker. + + String url = "jdbc:avatica:remote:url=http://localhost:8888/druid/v2/sql/avatica/";; Review Comment: Good catch, do you know if there's a reason why someone would want to connect to a specific Broker instead of going through the Router? -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
