docs/source/java/quickstart.rst

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==========
Quickstart
==========

Here we'll briefly tour basic features of ADBC with the PostgreSQL driver for Java.

Installation
============

To include ADBC in your Maven project, add the following dependency:

.. code-block:: xml

   <dependency>
       <groupId>org.apache.arrow.adbc</groupId>
       <artifactId>adbc-driver-jdbc</artifactId>
       <version>${adbc.version}</version>
   </dependency>

For the examples in this section, the following imports are required:

.. code-block:: java

   import org.apache.arrow.adbc.core.AdbcConnection;
   import org.apache.arrow.adbc.core.AdbcDatabase;
   import org.apache.arrow.adbc.core.AdbcDriver;
   import org.apache.arrow.adbc.core.AdbcException;
   import org.apache.arrow.adbc.core.AdbcStatement;

JDBC-style API
==============

ADBC provides a high-level API in the style of the JDBC standard.

Usage
-----

.. code-block:: java

   final Map<String, Object> parameters = new HashMap<>();
   parameters.put(AdbcDriver.PARAM_URL, "jdbc:postgresql://localhost:5432/postgres");
   try (
       BufferAllocator allocator = new RootAllocator();
       AdbcDatabase db = new JdbcDriver(allocator).open(parameters);
       AdbcConnection adbcConnection = db.connect();
       AdbcStatement stmt = adbcConnection.createStatement()

   ) {
       stmt.setSqlQuery("select * from foo");
       AdbcStatement.QueryResult queryResult = stmt.executeQuery();
       while (queryResult.getReader().loadNextBatch()) {
           // process batch
       }
   }  catch (AdbcException e) {
       // throw
   }

In application code, the connection must be closed after usage or memory may leak.
It is recommended to wrap the connection in a try-with-resources block for automatic
resource management.  In this example, we are connecting to a PostgreSQL database,
specifically the default database "postgres".

Note that creating a statement is also wrapped in the try-with-resources block.
Assuming we have a table "foo" in the database, an example for setting and executing the
query is also provided.