Question

我的表名为“highscore”，如下所示：
nameQL scoreQL
piotr 50

使用NAME和SCORE的Flash游戏以这个名字导出到PHP。

如何在PHP文件中创建：

IF（NAME存在于数据库中（nameQL）和分数＆gt; this.name.scoreQL）{Raplace scoreQL 使用SCORE WHERE nameQL = NAME}
IF（NAME不存在）{创建 NAME和SCORE的新行）

Answer 1

我会使用insert .. on duplicate key update ...语句。像这样：

insert into highscore set
    name = :name,
    score = :new_score
on duplicate key update
    score = greatest(score, :new_score)

name列应编入索引为unique。

测试脚本：

create table player (
    name varchar(32) primary key,
    score int not null default 0
);

-- create new players
insert into player set name = 'foo', score = 100
    on duplicate key update score = greatest(score, 100);
insert into player set name = 'bar', score = 100
    on duplicate key update score = greatest(score, 100);
insert into player set name = 'baz', score = 100
    on duplicate key update score = greatest(score, 100);

-- update score of existing player
insert into player set name = 'bar', score = 200
    on duplicate key update score = greatest(score, 200);

select * from player的输出：

+------+-------+
| name | score |
+------+-------+
| bar  |   200 |
| baz  |   100 |
| foo  |   100 |
+------+-------+

SQL：如果新条目更高，如何覆盖条目？否则创建新条目

1 个答案: