przykłady JDBC

pom.xml

@@ -50,6 +50,12 @@
 			<version>3.25.3</version>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.xerial</groupId>
+			<artifactId>sqlite-jdbc</artifactId>
+			<version>3.45.3.0</version>
+			<scope>runtime</scope>
+		</dependency>
 	</dependencies>
 
 </project>
\ No newline at end of file

src/main/java/sqlite/Grupowanie.java

+package sqlite;
+
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public class Grupowanie {
+
+	public static void main(String[] args) {
+		final String sql = """
+			SELECT job_id, job_title, count(employee_id), avg(salary), min(salary), max(salary)
+			FROM jobs LEFT JOIN employees USING(job_id)
+			GROUP BY job_id, job_title
+			ORDER BY 3 DESC, 2;
+		""";
+		try(Connection c = DriverManager.getConnection("jdbc:sqlite:hr.db");
+			PreparedStatement stmt = c.prepareStatement(sql);
+			ResultSet rs = stmt.executeQuery()) {
+			while(rs.next()) {
+				// odczyt wg numerów kolumn, numeracja od 1
+				System.out.printf("|%-10s| %-32s | %2d | %8.2f | %8.2f | %8.2f |%n",
+						rs.getString(1),
+						rs.getString(2),
+						rs.getInt(3),
+						rs.getBigDecimal(4),
+						rs.getBigDecimal(5),
+						rs.getBigDecimal(6));
+			}
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+	}
+
+}

src/main/java/sqlite/Odczyt1.java

+package sqlite;
+
+import java.math.BigDecimal;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public class Odczyt1 {
+
+	public static void main(String[] args) {
+		try {
+			Connection c = DriverManager.getConnection("jdbc:sqlite:hr.db");
+			System.out.println("Udało się połączyć. c = " + c);
+			PreparedStatement stmt = c.prepareStatement("SELECT * FROM employees");
+			ResultSet rs = stmt.executeQuery();
+			System.out.println("Mam wyniki: " + rs);
+			while(rs.next()) {
+				String firstName = rs.getString("first_name");
+				String lastName = rs.getString("last_name");
+				BigDecimal salary = rs.getBigDecimal("salary");
+				System.out.println(firstName + " " + lastName + " zarabia " + salary);
+			}
+			rs.close();
+			stmt.close();
+			c.close();
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+	}
+
+}

src/main/java/sqlite/Odczyt2.java

+package sqlite;
+
+import java.math.BigDecimal;
+import java.sql.Connection;
+import java.sql.DriverManager;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+
+public class Odczyt2 {
+
+	public static void main(String[] args) {
+		try(Connection c = DriverManager.getConnection("jdbc:sqlite:hr.db");
+			PreparedStatement stmt = c.prepareStatement("SELECT * FROM employees");
+			ResultSet rs = stmt.executeQuery()) {
+			while(rs.next()) {
+				String firstName = rs.getString("first_name");
+				String lastName = rs.getString("last_name");
+				BigDecimal salary = rs.getBigDecimal("salary");
+				System.out.println(firstName + " " + lastName + " zarabia " + salary);
+			}
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+	}
+
+}