Dostęp do bazy SQLite

pom.xml

@@ -12,4 +12,12 @@
 		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
 	</properties>
 
-</project>
\ No newline at end of file
+	<dependencies>
+		<dependency>
+			<groupId>org.xerial</groupId>
+			<artifactId>sqlite-jdbc</artifactId>
+			<version>3.42.0.0</version>
+			<scope>runtime</scope>
+		</dependency>
+	</dependencies>
+</project>

src/main/java/biblioteki/Sqlite1.java

+package biblioteki;
+
+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 Sqlite1 {
+
+	public static void main(String[] args) {
+		try {
+			Connection c = DriverManager.getConnection("jdbc:sqlite:hr.db");
+			System.out.println("Mam połączenie: " + c);
+			PreparedStatement stmt = c.prepareStatement("SELECT * FROM employees");
+			ResultSet rs = stmt.executeQuery();
+			while(rs.next()) {
+				int id = rs.getInt("employee_id");
+				String firstName = rs.getString("first_name");
+				String lastName = rs.getString("last_name");
+				BigDecimal salary = rs.getBigDecimal("salary");
+				System.out.println("Pracownik nr " + id + ": " + firstName + " " + lastName + " zarabia " + salary);
+			}
+			c.close();
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+	}
+
+}

src/main/java/biblioteki/Sqlite2.java

+package biblioteki;
+
+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 Sqlite2 {
+
+	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()) {
+				int id = rs.getInt("employee_id");
+				String firstName = rs.getString("first_name");
+				String lastName = rs.getString("last_name");
+				BigDecimal salary = rs.getBigDecimal("salary");
+				System.out.println("Pracownik nr " + id + ": " + firstName + " " + lastName + " zarabia " + salary);
+			}
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+	}
+
+}

src/main/java/biblioteki/SqliteMetadane.java

+package biblioteki;
+
+import java.sql.Connection;
+import java.sql.DatabaseMetaData;
+import java.sql.DriverManager;
+import java.sql.ResultSet;
+import java.sql.ResultSetMetaData;
+import java.sql.SQLException;
+
+public class SqliteMetadane {
+/* Nawet nie wiedząc jaka jest struktura bazy danych, można te informacje odczytać z połączenia */
+	public static void main(String[] args) {
+		try(Connection c = DriverManager.getConnection("jdbc:sqlite:hr.db")) {
+
+			System.out.println("Otwarto połączenie. c = " + c);
+			
+			DatabaseMetaData dbMetaData = c.getMetaData();
+			
+			System.out.println(dbMetaData.getDatabaseProductName());
+			System.out.println(dbMetaData.getDatabaseMajorVersion()
+					+ "." + dbMetaData.getDatabaseMinorVersion());
+			System.out.println();
+			
+			String[] coCzytac = {"TABLE"};
+			try(ResultSet tables = dbMetaData.getTables(null, "public", null, coCzytac)) {
+				wypiszTabele(tables);
+			}
+			System.out.println("\n\nNormalna tabela:");
+			
+			try(ResultSet rs = c.createStatement().executeQuery("SELECT * FROM jobs")) {
+				wypiszTabele(rs);				
+			}
+			System.out.println();
+			
+			try(ResultSet rs = c.createStatement().executeQuery("SELECT * FROM departments JOIN locations USING(location_id)")) {
+				wypiszTabele(rs);				
+			}
+		} catch (SQLException e) {
+			e.printStackTrace();
+		}
+	}
+
+	private static void wypiszTabele(ResultSet rs) throws SQLException {
+		// Odczytanie "metadanych wyniku"
+		ResultSetMetaData rsMetaData = rs.getMetaData();
+
+		final int n = rsMetaData.getColumnCount();
+		System.out.println("Wynik ma " + n + " kolumn:");
+		for(int i = 1; i <= n; i++) {
+			System.out.printf("%-30s", rsMetaData.getColumnName(i));
+		}
+		System.out.println();
+		for(int i = 1; i <= n; i++) {
+			System.out.printf("%-30s", rsMetaData.getColumnType(i));
+		}
+		System.out.println();
+		for(int i = 1; i <= n; i++) {
+			System.out.printf("%-30s", rsMetaData.getColumnTypeName(i));
+		}
+		System.out.println();
+		
+		while(rs.next()) {
+			for(int i = 1; i <= n; i++) {
+				System.out.printf("%-30s", rs.getString(i));
+			}
+			System.out.println();
+		}
+	}
+}