65 lines
2.3 KiB
Markdown
65 lines
2.3 KiB
Markdown
---
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layout: default_docs
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title: Geometric Data Types
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header: Chapter 9. PostgreSQL™ Extensions to the JDBC API
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resource: media
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previoustitle: Chapter 9. PostgreSQL™ Extensions to the JDBC API
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previous: ext.html
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nexttitle: Large Objects
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next: largeobjects.html
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---
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PostgreSQL™ has a set of data types that can store geometric features into a
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table. These include single points, lines, and polygons. We support these types
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in Java with the org.postgresql.geometric package. Please consult the Javadoc
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mentioned in [Chapter 13, *Further Reading*](reading.html) for details of
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available classes and features.
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<a name="geometric-circle-example"></a>
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**Example 9.1. Using the CIRCLE datatype JDBC**
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```java
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import java.sql.*;
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import org.postgresql.geometric.PGpoint;
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import org.postgresql.geometric.PGcircle;
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public class GeometricTest {
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public static void main(String args[]) throws Exception {
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String url = "jdbc:postgresql://localhost:5432/test";
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try (Connection conn = DriverManager.getConnection(url, "test", "")) {
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try (Statement stmt = conn.createStatement()) {
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stmt.execute("CREATE TEMP TABLE geomtest(mycirc circle)");
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}
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insertCircle(conn);
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retrieveCircle(conn);
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}
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}
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private static void insertCircle(Connection conn) throws SQLException {
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PGpoint center = new PGpoint(1, 2.5);
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double radius = 4;
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PGcircle circle = new PGcircle(center, radius);
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try (PreparedStatement ps = conn.prepareStatement("INSERT INTO geomtest(mycirc) VALUES (?)")) {
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ps.setObject(1, circle);
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ps.executeUpdate();
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}
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}
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private static void retrieveCircle(Connection conn) throws SQLException {
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try (Statement stmt = conn.createStatement()) {
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try (ResultSet rs = stmt.executeQuery("SELECT mycirc, area(mycirc) FROM geomtest")) {
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while (rs.next()) {
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PGcircle circle = (PGcircle)rs.getObject(1);
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double area = rs.getDouble(2);
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System.out.println("Center (X, Y) = (" + circle.center.x + ", " + circle.center.y + ")");
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System.out.println("Radius = " + circle.radius);
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System.out.println("Area = " + area);
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}
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}
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}
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}
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}
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```
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