我有一個工作腳本,用於選擇所有表中的圖像字段並在物理文件不存在時清空它們的值。優化PHP腳本
$query1 = "SELECT table_name,column_name
FROM information_schema.columns
WHERE table_schema='schemaname' AND column_name like '%image%' or column_name='video'";
$result1 = mysql_query($query1) or die(mysql_error() . " -- " . $query1);
while($row1 = mysql_fetch_row($result1)){
if (!strpos($row1[0],'backup') > 0){
$sql = "Select COLUMN_NAME FROM information_schema.columns WHERE TABLE_NAME = '".$row1[0]."' AND EXTRA = 'auto_increment'";
$resultcol = mysql_query($sql);
$rowcol = mysql_fetch_row($resultcol);
$query2 = "SELECT " . $row1[1] . ", " .$rowcol[0] . "
FROM " . $row1[0] . "
WHERE " . $row1[1] . " != '' AND " . $row1[1] . " IS NOT NULL
";
echo $query2 . "<br>";
$result2 = mysql_query($query2) or die(mysql_error() . " -- " . $query2);
while ($rowdb = mysql_fetch_row($result2)){
if (!strpos($rowdb[0],'facebook') > 0 && !file_exists($img_root.'/'.$rowdb[0])){
$sql = "UPDATE ".$row1[0]." SET ". $row1[1] . " = '' WHERE " . $rowcol[0]. "= ".$rowdb[1];
echo $sql . "<br><br>";
$delete_count++;
//mysql_query("UPDATE ".$row1[0]." SET ". $row1[1] . " = '' WHERE id = ".$row1["id"]);
}
}
}
}
腳本工作正常,但需要時間,雖然,我不知道是否有一個更聰明的方式(更優化),以獲得相同的功能?謝謝
http://codereview.stackexchange.com/ – j08691
這個問題似乎是題外話,因爲它屬於爲http://代碼審查.stackexchange.com/ –
您可以使用JOIN將前兩個查詢合併到一個查詢中。 – Barmar