mySQL / PHP：一行中的SQL语句，查询和结果分配？

Question

是否可以在一行（或简称为更短）中重写下面的代码，甚至是if (result > 0)语句？

// a simple query that ALWAYS gets ONE table row as result
$query  = $this->db->query("SELECT id FROM mytable WHERE this = that;");
$result = $query->fetch_object();
$id     = $result->id;

我见过很棒的，极其简化的结构，比如三元运算符（here和here - 顺便看到更多减少行的注释）将4-5行放在一个中，所以也许有些东西对于像上面这样的单个结果SQL查询。

Answer 1

你可以缩短

$query  = $this->db->query("SELECT id FROM mytable WHERE this = that;");
$result = $query->fetch_object();
$id     = $result->id;

到

$id = $this->db->query("SELECT id FROM mytable WHERE this = that")->fetch_object()->id;

但是，如果任何函数返回意外响应，原始代码将发出错误。最好写：

$query  = $this->db->query("SELECT id FROM mytable WHERE this = that");
if (!$query) {
     error_log('query() failed');
     return false;
}
$result = $query->fetch_object();
if (!$result) {
     error_log('fetch_object() failed');
     return false;
}
$id     = $result->id;