Java中的SQLITE刪除方法

Question

我有一種方法應該從我的數據庫中刪除一個Person（一行）。 我收到了我在捕獲中創建的錯誤消息。 我剛開始使用數據庫，並且我大多數時候一直在拼湊不同的技術。 我不確定該怎么辦

公共靜態無效deletePerson（String firstNameOfPersonToDelete，String lastNameOfPersonToDelete）{語句stmt = null;

    try {
        // Create database connection
        Connection c = DriverManager.getConnection("jdbc:sqlite:PERSON.db");

        // Create Statement object
        stmt = c.createStatement();

        // Get person we're about to delete
        String getPersonQuery = "SELECT SSN FIRSTNAME, LASTNAME, AGE, CREDITCARD FROM PERSON WHERE FIRSTNAME = '"
                + firstNameOfPersonToDelete + "' AND LASTNAME = '" + lastNameOfPersonToDelete + "'";
        ResultSet rs = stmt.executeQuery(getPersonQuery);

        String ssn = rs.getString("SSN");
        String firstName = rs.getString("FIRSTNAME");
        String lastName = rs.getString("LASTNAME");
        String age = rs.getString("AGE");
        String creditCard = rs.getString("CREDITCARD");

        String deletePersonStatement = "DELETE FROM PERSON WHERE FIRSTNAME = '" + firstName + "' AND LASTNAME = '"
                + lastName + "'";

        stmt.executeUpdate(deletePersonStatement);

        System.out.println("The following record was deleted:\n" + ssn + "\n" + firstName + " " + lastName + "\n"
                + age + "\n" + creditCard);
        System.out.println("\nThe database contains the following records: ");

        ArrayList<Object> myPeople = findAllPeople();

        for (Object element : myPeople) {
            System.out.println(element.toString());
        }

    } catch (SQLException e) {
        e.printStackTrace(System.err); 
        System.out.println("Error: The person: \"" + firstNameOfPersonToDelete + " " + lastNameOfPersonToDelete
                + "\" was not found. No records were deleted.");
        System.out.println("\nThe database contains the following records: ");
        ArrayList<Object> myPeople = findAllPeople();

        for (Object element : myPeople) {
            System.out.println(element.toString());
        }
    }
}

java.sql.SQLException：沒有這樣的列：'SSN'錯誤：找不到人員：“ Fitzgerald Grant”。 沒有記錄被刪除。 在org.sqlite.jdbc3.JDBC3ResultSet.findColumn（JDBC3ResultSet.java:48）在org.sqlite.jdbc3.JDBC3ResultSet.getString（JDBC3ResultSet.java:443）在Test.deletePerson（Test.java:181）在Test.main（ Test.java:65）

Answer 1

SELECT SSN FIRSTNAME, LASTNAME, AGE, CREDITCARD FROM ...
          ^

這與SSN AS FIRSTNAME相同，即，在查詢的輸出中， SSN列重命名為FIRSTNAME 。 您顯然忘記了逗號。

無論如何，您都將遇到此錯誤，因為沒有SSN列。 您必須確保使用此列創建該表，或者如果您具有舊數據庫，則必須添加此列。