Wrap-up

Querying a PostgreSQL Database in Java

Miller Trujillo

Staff Software Engineer

Connecting Java to PostgreSQL

Setting up JDBC for PostgreSQL
Executing SQL queries
Managing connections with try-with-resources

HikariConfig config = new HikariConfig();
config.setJdbcUrl("jdbc:postgresql://localhost:5432/library");
config.setUsername("postgres");
config.setPassword("secret");

HikariDataSource ds = new HikariDataSource(config);
try (Connection conn = ds.getConnection()) {
  ...
}

Advanced Query Techniques

Using PreparedStatement to protect against SQL injection
Filtering and sorting data
Working with joins and subqueries

String sql = "SELECT * FROM books WHERE title = ? and publication_year = ?";
PreparedStatement pstmt = conn.prepareStatement(sql);
pstmt.setString(1, "Alice in Wonderland");
pstmt.setInt(2, 1998);
ResultSet rs = pstmt.executeQuery();

Advanced Data Retrieval and Management

Aggregations and grouping
Transactions and batch processing
Working with Large Objects (LOBs)

Connection conn = DriverManager.getConnection(DB_URL, USERNAME, PASSWORD)
conn.setAutoCommit(false);
try (...) {
    // Execute your SQL statements here
    conn.commit();
} catch (SQLException e) {
  conn.rollback();
}

Congrats!

Querying a PostgreSQL Database in Java