MysqlndUhConnection::getFieldCount

(PECL mysqlnd-uh >= 1.0.0-alpha)

MysqlndUhConnection::getFieldCount — Returns the number of columns for the most recent query

说明

public int MysqlndUhConnection::getFieldCount ( mysqlnd_connection $connection )

Returns the number of columns for the most recent query.

参数

connection: Mysqlnd connection handle. Do not modify!

返回值

Number of columns.

范例

MysqlndUhConnection::getFieldCount() is not only executed after the invocation of a user space API call which maps directly to it but also called internally.

Example #1 MysqlndUhConnection::getFieldCount() example

  <?php
 class  proxy  extends  MysqlndUhConnection  {
 public function  getFieldCount ( $res ) {
    printf ( "%s(%s)\n" ,  __METHOD__ ,  var_export ( func_get_args (),  true ));
    $ret  =  parent :: getFieldCount ( $res );
    printf ( "%s returns %s\n" ,  __METHOD__ ,  var_export ( $ret ,  true ));
   return  $ret ;
 }
}
 mysqlnd_uh_set_connection_proxy (new  proxy ());

 $mysqli  = new  mysqli ( "localhost" ,  "root" ,  "" ,  "test" );
 $mysqli -> query ( "WILL_I_EVER_LEARN_SQL?" );
 var_dump ( $mysqli -> field_count );
 $mysqli -> query ( "SELECT 1, 2, 3 FROM DUAL" );
 var_dump ( $mysqli -> field_count );
 ?>

以上例程会输出：

proxy::getFieldCount(array (
  0 => NULL,
))
proxy::getFieldCount returns 0
int(0)
proxy::getFieldCount(array (
  0 => NULL,
))
proxy::getFieldCount returns 3
proxy::getFieldCount(array (
  0 => NULL,
))
proxy::getFieldCount returns 3
int(3)

参见

mysqlnd_uh_set_connection_proxy() - Installs a proxy for mysqlnd connections
mysqli_field_count() - Returns the number of columns for the most recent query