Why can't I search for Chinese characters only by English letters?

Why can't I search for Chinese characters only by English letters? For example, why can't I search for English letters or Chinese characters in a PHP site?
After searching for Chinese characters, the screen is blank. please give me some advice!

 
 Query instances
 $ Value) {echo"
 
 
  
  
"; Echo"
  
  "; Echo" 
  
 
   
 
    
$ Value [title]
 
   
 
 
";}?>

Reply to discussion (solution)

Print the SQL statement to check whether the SQL statement is normal (the main reason is that the obtained Chinese parameters may be garbled.

Print the SQL statement to check whether the SQL statement is normal (the main reason is that the obtained Chinese parameters may be garbled.
It is not a garbled problem. The key is that the search Chinese is not displayed, and the search numbers and letters are displayed normally.



It's not a coding problem. I tried your code and it's useless.
The key is to search for Chinese characters without any Display. The search numbers and letters are displayed normally.

Print SQL directly to check whether the database has a value.