Bosses, you have a question about the problem of query, specific I also say not clear, please see the following code:

 
//code a 
$data=https://bbs.csdn.net/topics/array (a, b, c, d);//the array may have 1000 data 
for($i=0; $iWhere $SQL="select * from XXX yyy=". The data [I]; 
$list=query ($SQL); 
If (mysqli_num_rows ($list) & gt; 0 {
.//here to complete the task 
} 
} 

 
//code 2 
$data=https://bbs.csdn.net/topics/array (a, b, c, d);//the array may have 1000 data 
$SQL="select * from XXX"; 
$list=query ($SQL); 
$mem=array (); 
Foreth ($list as $row) {
$mem []=$row; 
} 

for($i=0; $iFor ($j=0; $j=count ($mem); {$j++) 
If ($mem [$j] [" yyy "]==$data [$I]) {
.//here to complete the task 
} 
} 
} 

Excuse me, these two code, which is better, why