如何使用 java 从 mysql 数据库返回多行

Question

I want to select multiple rows and return them in an Arraylist.

My Database structure looks like this:

1   Bestellnummer   int(20)     
2   BestellerID int(20)         
3   ArtikelNummer   int(20)         
4   Anzahl  int(10)         
5   Preis   double  

It doesnt have a unique key, since it will not be changed. I wrote this Method but i get the error:

" You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'BestellerID,ArtikelNummer,Preis FROM bestellungen WHERE Bestellnummer = 1' at line 1Exception in thread "main" java.lang.IndexOutOfBoundsException: Index 1 out-of-bounds for length 0"

public ArrayList<Bestellung> getBestellung (int i) throws SQLException {
        ArrayList<Bestellung> Auftrag = new ArrayList<>();
        final String SQL ="SELECT*  BestellerID,ArtikelNummer,Preis FROM bestellungen WHERE Bestellnummer = ?" ;

        ResultSet rs = null ;
        try {
        PreparedStatement stmt = con.prepareStatement(SQL,ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
        stmt.setInt(1, i);
        rs = stmt.executeQuery();
        System.out.println("test");

        while (rs.next()) {     
            Bestellung test = new Bestellung( i,  rs.getInt("BestellerID"), rs.getInt("ArtikelNummer"), rs.getDouble("Preis"));
            Auftrag.add(test);

        }
        }
         catch (SQLException e) {
                System.err.print(e);
            }
         finally {
             if (rs!=null) {rs.close();
            }
         }
        return Auftrag;
                    }
}
public class Bestellung {
private int Bestellnummer, BestellerID,ArtikelNummer,Anzahl;
private double Preis;

Here is the Class that Objects will be in the Arraylist:

Bestellung (int Bestellnummerin,int BestellerIDin,int ArtikelNummerin,double Preisin)
{ 
this.Bestellnummer = Bestellnummerin ;
this.BestellerID = BestellerIDin ;
this.ArtikelNummer = ArtikelNummerin;
this.Anzahl = 1;
this.Preis = Preisin;
}}

Answer 1

You can try this:

final String SQL ="SELECT BestellerID,ArtikelNummer,Preis 
                  FROM bestellungen WHERE Bestellnummer = ?";