Question

我想插入一个条目，如果它不存在，否则更新条目，我无法使用ON DUPLICATE KEY UPDATE，我对语法感到困惑。所以我试着做这样的事情：

    final String QUERY = "REPLACE INTO skills SET VALUES (" + insert(player) + ") WHERE playername = '" + player.getUsername() + "'";
    statement.execute(QUERY);

    statement.close();
    connection.close();
}

private static String insert(Player player) {
    String stringToReturn = "'" + player.getUsername() + "',";
    for (int index = 0; index < 25; index++) {
        stringToReturn += player.getSkills().getLevels()[index] + "," + ((int) player.getSkills().getXp()[index]) + ",";
    }
    stringToReturn = stringToReturn.substring(0, stringToReturn.length() - 1);
    return stringToReturn;
}

但那是不正确的语法，所以我想知道如何做到这一点？

playername是主键

Answer 1

我认为使ON DUPLICATE KEY UPDATE正常工作的正确语法是：

"INSERT INTO skills (playerName, otherColumn) 
    VALUES ('" + player.getUsername() + "', '" + insert(player) +"')
 ON DUPLICATE KEY UPDATE otherColumn = VALUES(otherColumn)";

如果不存在则插入mysql条目，如果它存在java则更新

1 个答案: