How can SQL queries be executed via JDBC in Java?

In Java, executing SQL queries via JDBC can be done in several ways:

1. Statement — used for executing simple SQL queries without parameters.

Statement stmt = connection.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM users");

2. PreparedStatement — allows executing parameterized queries, which enhances security (protection against SQL injection) and performance when called repeatedly.

PreparedStatement pstmt = connection.prepareStatement("SELECT * FROM users WHERE id = ?");
pstmt.setInt(1, 10);
ResultSet rs = pstmt.executeQuery();

3. CallableStatement — used for calling stored procedures in the database.

CallableStatement cstmt = connection.prepareCall("{call getUserById(?)}");
cstmt.setInt(1, 10);
ResultSet rs = cstmt.executeQuery();

Each of these methods is suitable for different tasks depending on the complexity and security requirements of the queries.