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README.md

dw-jdbc

dw-jdbc is a JDBC driver for connecting to datasets hosted on data.world. It can be used to provide read-only access to any dataset provided by data.world from any JVM language. dw-jdbc supports query access both in dwSQL (data.world's SQL dialect) and in SPARQL 1.1, the native query language for semantic web data sources.

JDBC URLs

JDBC connects to data source based on a provided JDBC url. data.world JDBC urls have the form

jdbc:data:world:[language]:[user id]:[dataset id]

where:

  • [language] is either sql or sparql
  • [user id] is the data.world id of the dataset owner
  • [dataset id] is the data.world id of the dataset

You can extract these ids from the dataset home page url: https://data.world/[user id]/[dataset id].

Sample code (Java 8)

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;


final String QUERY = "select * from HallOfFame where playerID = ? order by yearid, playerID limit 10";
final String URL = "jdbc:data:world:sql:dave:lahman-sabremetrics-dataset";


try (final Connection connection =    // get a connection to the database, which will automatically be closed when done
         DriverManager.getConnection(URL, "<your user name>", "<your API token>");
     final PreparedStatement statement = // get a connection to the database, which will automatically be closed when done
         connection.prepareStatement(QUERY)) {
    statement.setString(1, "alexape01"); //bind a query parameter
    try (final ResultSet resultSet = statement.executeQuery()) { //execute the query
        ResultSetMetaData rsmd = resultSet.getMetaData();  //print out the column headers
        int columnsNumber = rsmd.getColumnCount();
        for (int i = 1; i <= columnsNumber; i++) {
            if (i > 1) System.out.print(",  ");
            System.out.print(rsmd.getColumnName(i));
        }
        System.out.println("");
        while (resultSet.next()) { //loop through the query results
            for (int i = 1; i <= columnsNumber; i++) { //print out the column headers
                if (i > 1) System.out.print(",  ");
                String columnValue = resultSet.getString(i);
                System.out.print(columnValue);
            }
            System.out.println("");

            // Note: when calling ResultSet.getObject() prefer the version that takes an explicit Class argument:
            // Integer n = resultSet.getObject(param, Integer.class);
        }
    }
}

Using dw-jdbc in your project

If using Maven, you can use dw-jdbc by just including the following in your pom.xml file:

<dependency>
    <groupId>world.data</groupId>
    <artifactId>dw-jdbc</artifactId>
    <version>0.4.1</version>
</dependency>

See this link at Maven Central to find the latest version number for the JDBC driver.

For some database tools it's easier to install the jdbc driver if it's a single jar. For this reason we also provide dw-jdbc bundled with all its dependencies under the following:

<dependency>
    <groupId>world.data</groupId>
    <artifactId>dw-jdbc</artifactId>
    <classifier>shaded</classifier>
    <version>0.4.1</version>
</dependency>

Finding your Token

  1. Visit https://data.world
  2. Visit your user settings, and click the advanced tab.
  3. Copy your token.

Features

  • JDBC 4.2

  • The driver only supports read-only queries. It does not support INSERT/UPDATE/DELETE, DDL, or transactions.

  • Queries can be written in SPARQL 1.1 or in the SQL dialect described at https://docs.data.world/tutorials/dwsql/.

  • [SQL-only] Table and column metadata via java.sql.DatabaseMetaData.

  • [SQL-only] Support for positional parameters via java.sql.PreparedStatement.

  • [SPARQL-only] Support for named parameters via java.sql.CallableStatement.

    • For example, CallableStatement.setString("name", "value") will bind the string value to ?name within the query.
  • The DataWorldStatement.setJdbcCompatibilityLevel(JdbcCompatibility) method can be used to adjust how the JDBC driver maps query results to Java objects in java.sql.ResultSetMetaData. This is particularly relevant to SPARQL queries where result types in a column can vary from row to row.

    • JdbcCompatibility.LOW - No assumptions are made about types. ResultSetMetaData.getColumnType() returns java.sql.Types.OTHER and ResultSet.getObject() returns world.data.jdbc.model.Node.

    • JdbcCompatibility.MEDIUM - [SPARQL default] All columns are typed as string. ResultSetMetaData.getColumnType() returns java.sql.Types.NVARCHAR and ResultSet.getObject() returns java.lang.String.

    • JdbcCompatibility.HIGH - [SQL default] Columns are typed based on the underlying data, either using table metadata (SQL) or by inspecting the first row of the response (SPARQL).