JDBC

JDBC

NOTICE: CURRENTLY, JDBC IS USED FOR CONNECTING SOME THIRD-PART TOOLS. IT CAN NOT PROVIDE HIGH THROUGHPUT FOR WRITE OPERATIONS. PLEASE USE JAVA NATIVE APIopen in new window INSTEAD

Dependencies

JDK >= 1.8
Maven >= 3.6

Installation

In root directory:

1. mvn clean install -pl iotdb-client/jdbc -am -Dmaven.test.skip=true

Use IoTDB JDBC with Maven

1. <dependencies>
2. <dependency>
3. <groupId>org.apache.iotdb</groupId>
4. <artifactId>iotdb-jdbc</artifactId>
5. <version>0.12.0</version>
6. </dependency>
7. </dependencies>

Coding Examples

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.

1. import java.sql.*;
2. import org.apache.iotdb.jdbc.IoTDBSQLException;

4. public class JDBCExample {
5. /**
6. * Before executing a SQL statement with a Statement object, you need to create a Statement object using the createStatement() method of the Connection object.
7. * After creating a Statement object, you can use its execute() method to execute a SQL statement
8. * Finally, remember to close the 'statement' and 'connection' objects by using their close() method
9. * For statements with query results, we can use the getResultSet() method of the Statement object to get the result set.
10. */
11. public static void main(String[] args) throws SQLException {
12. Connection connection = getConnection();
13. if (connection == null) {
14. System.out.println("get connection defeat");
15. return;
16. }
17. Statement statement = connection.createStatement();
18. //Create database
19. try {
20. statement.execute("CREATE DATABASE root.demo");
21. }catch (IoTDBSQLException e){
22. System.out.println(e.getMessage());
23. }

26. //SHOW DATABASES
27. statement.execute("SHOW DATABASES");
28. outputResult(statement.getResultSet());

30. //Create time series
31. //Different data type has different encoding methods. Here use INT32 as an example
32. try {
33. statement.execute("CREATE TIMESERIES root.demo.s0 WITH DATATYPE=INT32,ENCODING=RLE;");
34. }catch (IoTDBSQLException e){
35. System.out.println(e.getMessage());
36. }
37. //Show time series
38. statement.execute("SHOW TIMESERIES root.demo");
39. outputResult(statement.getResultSet());
40. //Show devices
41. statement.execute("SHOW DEVICES");
42. outputResult(statement.getResultSet());
43. //Count time series
44. statement.execute("COUNT TIMESERIES root");
45. outputResult(statement.getResultSet());
46. //Count nodes at the given level
47. statement.execute("COUNT NODES root LEVEL=3");
48. outputResult(statement.getResultSet());
49. //Count timeseries group by each node at the given level
50. statement.execute("COUNT TIMESERIES root GROUP BY LEVEL=3");
51. outputResult(statement.getResultSet());

54. //Execute insert statements in batch
55. statement.addBatch("insert into root.demo(timestamp,s0) values(1,1);");
56. statement.addBatch("insert into root.demo(timestamp,s0) values(1,1);");
57. statement.addBatch("insert into root.demo(timestamp,s0) values(2,15);");
58. statement.addBatch("insert into root.demo(timestamp,s0) values(2,17);");
59. statement.addBatch("insert into root.demo(timestamp,s0) values(4,12);");
60. statement.executeBatch();
61. statement.clearBatch();

63. //Full query statement
64. String sql = "select * from root.demo";
65. ResultSet resultSet = statement.executeQuery(sql);
66. System.out.println("sql: " + sql);
67. outputResult(resultSet);

69. //Exact query statement
70. sql = "select s0 from root.demo where time = 4;";
71. resultSet= statement.executeQuery(sql);
72. System.out.println("sql: " + sql);
73. outputResult(resultSet);

75. //Time range query
76. sql = "select s0 from root.demo where time >= 2 and time < 5;";
77. resultSet = statement.executeQuery(sql);
78. System.out.println("sql: " + sql);
79. outputResult(resultSet);

81. //Aggregate query
82. sql = "select count(s0) from root.demo;";
83. resultSet = statement.executeQuery(sql);
84. System.out.println("sql: " + sql);
85. outputResult(resultSet);

87. //Delete time series
88. statement.execute("delete timeseries root.demo.s0");

90. //close connection
91. statement.close();
92. connection.close();
93. }

95. public static Connection getConnection() {
96. // JDBC driver name and database URL
97. String driver = "org.apache.iotdb.jdbc.IoTDBDriver";
98. String url = "jdbc:iotdb://127.0.0.1:6667/";
99. // set rpc compress mode
100. // String url = "jdbc:iotdb://127.0.0.1:6667?rpc_compress=true";

102. // Database credentials
103. String username = "root";
104. String password = "root";

106. Connection connection = null;
107. try {
108. Class.forName(driver);
109. connection = DriverManager.getConnection(url, username, password);
110. } catch (ClassNotFoundException e) {
111. e.printStackTrace();
112. } catch (SQLException e) {
113. e.printStackTrace();
114. }
115. return connection;
116. }

118. /**
119. * This is an example of outputting the results in the ResultSet
120. */
121. private static void outputResult(ResultSet resultSet) throws SQLException {
122. if (resultSet != null) {
123. System.out.println("--------------------------");
124. final ResultSetMetaData metaData = resultSet.getMetaData();
125. final int columnCount = metaData.getColumnCount();
126. for (int i = 0; i < columnCount; i++) {
127. System.out.print(metaData.getColumnLabel(i + 1) + " ");
128. }
129. System.out.println();
130. while (resultSet.next()) {
131. for (int i = 1; ; i++) {
132. System.out.print(resultSet.getString(i));
133. if (i < columnCount) {
134. System.out.print(", ");
135. } else {
136. System.out.println();
137. break;
138. }
139. }
140. }
141. System.out.println("--------------------------\n");
142. }
143. }
144. }

The parameter version can be used in the url:

1. String url = "jdbc:iotdb://127.0.0.1:6667?version=V_1_0";

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, V_1_0.

JDBC (Not Recommend)

JDBC

Dependencies

Installation

Use IoTDB JDBC with Maven

Coding Examples