PHP脚本处理NULL值：
可以使用IF ... ELSE条件准备的基础上操作NULL值的查询。
例子:
下面的示例tutorial_count从外部，然后它与可在表中的值进行比较。
| <?php $dbhost = 'localhost:3036'; $dbuser = 'root'; $dbpass = 'rootpassword'; $conn = mysql_connect($dbhost, $dbuser, $dbpass); if(! $conn ) { die('Could not connect: ' . mysql_error()); } if( isset($tutorial_count )) { $sql = 'SELECT tutorial_author, tutorial_count FROM tcount_tbl WHERE tutorial_count = $tutorial_count'; } else { $sql = 'SELECT tutorial_author, tutorial_count FROM tcount_tbl WHERE tutorial_count IS $tutorial_count'; } mysql_select_db('TUTORIALS'); $retval = mysql_query( $sql, $conn ); if(! $retval ) { die('Could not get data: ' . mysql_error()); } while($row = mysql_fetch_array($retval, MYSQL_ASSOC)) { echo "Author:{$row['tutorial_author']} <br> ". "Count: {$row['tutorial_count']} <br> ". "--------------------------------<br>"; } echo "Fetched data successfullyn"; mysql_close($conn); ?> |
