Destoon two times to develop common database operation _php instance

Destoon the system automatically connects the database after the system is initialized and saves the database operations object to $DB. For database operation methods please refer to the Include/db_mysql.class.php function prototype, the following examples of common database operations.

1. Execute SQL statement

$db->query ("INSERT into ' {$DT _pre}table ' (' xxx ') VALUES (' yyy ')");

$db->query ("UPDATE" {$DT _pre}table ' SET ' xxx ' = ' yyy ' WHERE ' zzz ' = 1 ');

$db->query ("DELETE from ' {$DT _pre}table ' WHERE ' zzz ' = 1");

2. Read more information

$A = Array ();
$result = $db->query ("select * from ' {$DT _pre}table ' WHERE ' xxx ' = ' yyy ' ORDER by ' zzz ' DESC LIMIT 0,10");
while ($r = $db->fetch_array ($result)) {
  $A [] = $r;
}
Print_r ($A);

3. Read a single message

$A = $db->get_one ("select * from ' {$DT _pre}table ' WHERE ' xxx ' = ' yyy '");
Print_r ($A);

4, the total number of calculations

$A = $db->get_one ("Select COUNT (*) as num from ' {$DT _pre}table ' WHERE ' xxx ' = ' yyy '");
echo $A [' num '];

The system's table prefixes can be used in variable $dt_pre (commonly used in statements) or $db->pre (commonly used in functions).
If you use database operations in a function, you need to first perform a global $db;