将数据库表数据插入数组中

Question

我想将数据插入数组，以便可以访问特定值并显示它们。我是Java的新手，我希望答案很简单。

try {
    Statement stmt = conn.createStatement();
    String sql = "SELECT * FROM " + tableName;
    ResultSet results = stmt.executeQuery(sql);
    ResultSetMetaData rsmt = results.getMetaData();
    int numberOfColumns = rsmt.getColumnCount();

    for (int i = 1; i <= numberOfColumns; i++) {
        System.out.print(rsmt.getColumnLabel(i) + "\t\t\t");
    }

    System.out.println("\n-------------------------------------------------------------------------------");

    while (results.next()) {
        int s_no = results.getInt(1);
        String s_name = results.getString(2);
        String s_surname = results.getString(3);

        System.out.println(s_no + "\t\t\t" + s_name + "\t\t\t" + s_surname);
    }

    results.close();
    stmt.close();

} catch (Exception e) {
    JOptionPane.showMessageDialog(null, "Records were not returned", "Error", JOptionPane.ERROR_MESSAGE);
    System.out.println(e.getMessage());
}

Answer 1

无法将结果集数据存储在数组中。

更好地创建pojo类学生

public class Student {
     private int s_no;
     private String s_name;
     private String s_surname;

    public int getS_no() {
        return s_no;
    }
    public void setS_no(int s_no) {
        this.s_no = s_no;
    }
    public String getS_name() {
        return s_name;
    }
    public void setS_name(String s_name) {
        this.s_name = s_name;
    }
    public String getS_surname() {
        return s_surname;
    }
    public void setS_surname(String s_surname) {
        this.s_surname = s_surname;
    }

}

存储逻辑：-

ResultSet results = stmt.executeQuery(sql);
    List<Student> studs = new ArrayList<Student>();
    while (results.next()){

            Student stud = new Student();
            stud.setS_no(results.getInt(1));
            stud.setS_name(results.getString(2));
            stud.setS_surname(results.getString(3));
            studs.add(stud);
       }

所有学生都已添加到列表中。请循环访问此列表以获取学生数据。

希望这对您有用