PHP MYSQL mysql_num_fields 和 mysql_num_rows 函数– 根据查询获得结果的列数和行数

mysql_num_fields用于获得查询结果的列数，如果执行成功返回列数，执行失败，返回boolean值

<?php
$UserName = 'abc';
$Password = '1234';
$DbHandle = mysql_connect ('localhost', $UserName, $Password);
if (!$DbHandle) {
  die 'No database connection could be established.';
}
 
$DBName = 'w3db;
if (!mysql_select_db ($DBName, $DbHandle)) {
  die 'Database could not be selected.';
}
$Query = "SELECT ISBN, Title, Author FROM articles";
$articles = mysql_query ($Query, $DbHandle));
 
$RowCount = mysql_num_rows ($articles);
$FieldCount = mysql_num_fields ($articles);
$I = 0;
while ($I < $RowCount) {
  $Row = mysql_fetch_assoc ($articles);
  echo "Row $I<br />\n";
  $J = 0;
  while ($J < $FieldCount) {
    echo "$Row[$J]<br />\n";
    ++$J;
  }
  ++$I;
}
 
mysql_close ($DbHandle);
?>