NOTICE: CURRENTLY, JDBC IS USED FOR CONNECTING SOME THIRD-PART TOOLS. IT CAN NOT PROVIDE HIGH THROUGHPUT FOR WRITE OPERATIONS. PLEASE USE JAVA NATIVE API INSTEAD
In root directory:
mvn clean install -pl jdbc -am -Dmaven.test.skip=true
<dependencies> <dependency> <groupId>org.apache.iotdb</groupId> <artifactId>iotdb-jdbc</artifactId> <version>0.12.0</version> </dependency> </dependencies>
This chapter provides an example of how to open a database connection, execute a SQL query, and display the results.
It requires including the packages containing the JDBC classes needed for database programming.
NOTE: For faster insertion, the insertTablet() in Session is recommended.
import java.sql.*; import org.apache.iotdb.jdbc.IoTDBSQLException; public class JDBCExample { /** * Before executing a SQL statement with a Statement object, you need to create a Statement object using the createStatement() method of the Connection object. * After creating a Statement object, you can use its execute() method to execute a SQL statement * Finally, remember to close the 'statement' and 'connection' objects by using their close() method * For statements with query results, we can use the getResultSet() method of the Statement object to get the result set. */ public static void main(String[] args) throws SQLException { Connection connection = getConnection(); if (connection == null) { System.out.println("get connection defeat"); return; } Statement statement = connection.createStatement(); //Create storage group try { statement.execute("SET STORAGE GROUP TO root.demo"); }catch (IoTDBSQLException e){ System.out.println(e.getMessage()); } //Show storage group statement.execute("SHOW STORAGE GROUP"); outputResult(statement.getResultSet()); //Create time series //Different data type has different encoding methods. Here use INT32 as an example try { statement.execute("CREATE TIMESERIES root.demo.s0 WITH DATATYPE=INT32,ENCODING=RLE;"); }catch (IoTDBSQLException e){ System.out.println(e.getMessage()); } //Show time series statement.execute("SHOW TIMESERIES root.demo"); outputResult(statement.getResultSet()); //Show devices statement.execute("SHOW DEVICES"); outputResult(statement.getResultSet()); //Count time series statement.execute("COUNT TIMESERIES root"); outputResult(statement.getResultSet()); //Count nodes at the given level statement.execute("COUNT NODES root LEVEL=3"); outputResult(statement.getResultSet()); //Count timeseries group by each node at the given level statement.execute("COUNT TIMESERIES root GROUP BY LEVEL=3"); outputResult(statement.getResultSet()); //Execute insert statements in batch statement.addBatch("insert into root.demo(timestamp,s0) values(1,1);"); statement.addBatch("insert into root.demo(timestamp,s0) values(1,1);"); statement.addBatch("insert into root.demo(timestamp,s0) values(2,15);"); statement.addBatch("insert into root.demo(timestamp,s0) values(2,17);"); statement.addBatch("insert into root.demo(timestamp,s0) values(4,12);"); statement.executeBatch(); statement.clearBatch(); //Full query statement String sql = "select * from root.demo"; ResultSet resultSet = statement.executeQuery(sql); System.out.println("sql: " + sql); outputResult(resultSet); //Exact query statement sql = "select s0 from root.demo where time = 4;"; resultSet= statement.executeQuery(sql); System.out.println("sql: " + sql); outputResult(resultSet); //Time range query sql = "select s0 from root.demo where time >= 2 and time < 5;"; resultSet = statement.executeQuery(sql); System.out.println("sql: " + sql); outputResult(resultSet); //Aggregate query sql = "select count(s0) from root.demo;"; resultSet = statement.executeQuery(sql); System.out.println("sql: " + sql); outputResult(resultSet); //Delete time series statement.execute("delete timeseries root.demo.s0"); //close connection statement.close(); connection.close(); } public static Connection getConnection() { // JDBC driver name and database URL String driver = "org.apache.iotdb.jdbc.IoTDBDriver"; String url = "jdbc:iotdb://127.0.0.1:6667/"; // set rpc compress mode // String url = "jdbc:iotdb://127.0.0.1:6667?rpc_compress=true"; // Database credentials String username = "root"; String password = "root"; Connection connection = null; try { Class.forName(driver); connection = DriverManager.getConnection(url, username, password); } catch (ClassNotFoundException e) { e.printStackTrace(); } catch (SQLException e) { e.printStackTrace(); } return connection; } /** * This is an example of outputting the results in the ResultSet */ private static void outputResult(ResultSet resultSet) throws SQLException { if (resultSet != null) { System.out.println("--------------------------"); final ResultSetMetaData metaData = resultSet.getMetaData(); final int columnCount = metaData.getColumnCount(); for (int i = 0; i < columnCount; i++) { System.out.print(metaData.getColumnLabel(i + 1) + " "); } System.out.println(); while (resultSet.next()) { for (int i = 1; ; i++) { System.out.print(resultSet.getString(i)); if (i < columnCount) { System.out.print(", "); } else { System.out.println(); break; } } } System.out.println("--------------------------\n"); } } }
The parameter version
can be used in the url:
String url = "jdbc:iotdb://127.0.0.1:6667?version=V_0_12";
The parameter version
represents the SQL semantic version used by the client, which is used to be compatible with the SQL semantics of 0.12 when upgrading 0.13. The possible values are: V_0_12
, V_0_13
.