僅當值大於當前值時才更新字段的SQL語句

Question

到目前為止，我有這樣的聲明：

String query = "UPDATE Score SET Points = "+scorecard[TOTAL][i]+" WHERE Name = "+players[i].getName()+" AND Lastname = "+players[i].getLastName()";

知道我應該怎么做嗎？ 我看到某處使用CASE WHEN語法但無法使其工作。

Answer 1

你想要的

update score set points = ? where
      name = ? and lastname = ?
      and points < ?

作為SQL。 請使用PreparedStatement。

try(PreparedStatement ps = con.prepareStatement("update score set " + 
     " points = ? where name = ? and lastname = ? and points < ?") {
  ps.setInt(1, scorecard[TOTAL][i]);
  ps.setString(2, players[i].getName());
  ps.setString(3, players[i].getLastName());
  ps.setInt(4, scorecard[TOTAL][i]);
  ps.executeUpdate(); 
}