Handling Database Exceptions
Database operations can fail for several reasons: a table may not exist, a column name may be misspelled, or the connection may drop. JDBC uses SQLException to capture these errors, providing details like error messages and SQL state codes.
The query in this exercise has an intentional typo (boks instead of books).
本练习是课程的一部分
Querying a PostgreSQL Database in Java
练习说明
- Catch the exception when the query fails.
- Print the error message and SQLState from the exception.
交互式实操练习
通过完成这段示例代码来试试这个练习。
public class Main {
public static void main(String[] args) {
try (Connection conn = DriverManager.getConnection(Credentials.URL, Credentials.USER, Credentials.PASSWORD);
Statement stmt = conn.createStatement();
ResultSet rs = stmt.executeQuery("SELECT * FROM boks")) {
while (rs.next()) {
System.out.println(rs.getString("title"));
System.out.println(rs.getInt("publication_year"));
}
// Catch database exceptions
} catch (____ e) {
// Print the error message and SQLState
System.out.println("Error: " + e.____());
System.out.println("SQLState: " + e.____());
}
}
}