Checks whether MySQL forms are empty and empty functions are available.

The following article mainly introduces php's use of the empty function to determine whether MySQL forms are empty. We all know that php does not have a direct function to determine whether database fields are empty, however, we can use the return function of MySQL_fetch_array.

Value.

For example.

Php uses the empty function to determine whether MySQL forms are empty. Method 1:

 
 

  
  
$sql = "select * form abc" 
  
  
$result = MySQL_query($sql);  
  
  
$row = MySQL_fetch_array($result); 
 
 

If (empty ($ row) // start to judge whether it is null

 
 

  
  
{  
  
  
echo "null";  
  
  
}  
  
  
else  
  
  
{  
  
  
echo "not null";  
  
  
} 
 
 

Php uses the empty function to determine whether MySQL forms are empty. Method 2:

 
 

  
  
$sql = "select * form abc" 
  
  
$result = MySQL_query($sql);  
  
  
$row = MySQL_fetch_array($result); 
 
 

If (! $ Row) // It is null enough to start judgment.

 
 

  
  
{  
  
  
echo "null";  
  
  
}  
  
  
else  
  
  
{  
  
  
echo "not null";  
  
  
} 
 
 

In fact, when the MySQL_fetch_array function is used, if the table is an empty table, false is returned. At this time, $ row is not successfully assigned a value. Remember, never dare to use it like this

 
 

  
  
$row =  mysql _fetch_array($result)or die(mysql_error()); 
 
 

If the program is followed by yo or die, the execution of mysql_fetch_array will be terminated. The above content is an introduction to php's use of the empty function to determine whether the MySQL form is empty.