Question

我想知道这个想法是否是更新数据库中表格行的好习惯。

我通常更新这样的行，

$pg_id = set_variable($_POST,'pg_id');
$pg_url = set_variable($_POST,'pg_url');
$pg_title = set_variable($_POST,'pg_title');
$pg_subtitle = set_variable($_POST,'pg_subtitle');
$pg_description = set_variable($_POST,'pg_description');
$pg_introduction = set_variable($_POST,'pg_introduction');
$pg_content_1 = set_variable($_POST,'pg_content_1');
$pg_content_2 = set_variable($_POST,'pg_content_2');
$pg_content_3 = set_variable($_POST,'pg_content_3');
$pg_content_4 = set_variable($_POST,'pg_content_4');
$pg_backdate = set_variable($_POST,'pg_backdate');
$pg_tag = set_variable($_POST,'pg_tag');
$pg_user = set_variable($_POST,'pg_user');
$pg_member = set_variable($_POST,'pg_member');
$pg_highlight = set_variable($_POST,'pg_highlight');
$pg_hide = set_variable($_POST,'pg_hide');
$pg_cat_id = set_variable($_POST,'pg_cat_id');
$ps_cat_id = set_variable($_POST,'ps_cat_id'); 
$parent_id = set_variable($_POST,'parent_id');
$tmp_id = set_variable($_POST,'tmp_id');
$usr_id = set_variable($_POST,'usr_id');

$sql = "
UPDATE root_pages
SET 
    pg_url = ?, 
    pg_title = ?,
    pg_subtitle = ?,
    pg_backdate = ?,
    pg_description = ?,
    pg_introduction = ?,        
    pg_content_1 = ?,
    pg_content_2 = ?,
    pg_content_3 = ?,
    pg_content_4 = ?,
    pg_highlight = ?,
    pg_hide = ?,
    ps_cat_id = ?,  
    parent_id = ?, 
    tmp_id = ?,
    updated_by = ?
WHERE pg_id = ?
";

# use the instantiated db connection object from the init.php, to process the query
$result = $connection->run_query($sql,array(
    $pg_url, 
    $pg_title,
    $pg_subtitle,
    $pg_backdate,
    $pg_description,
    $pg_introduction,
    $pg_content_1,
    $pg_content_2,
    $pg_content_3,
    $pg_content_4,
    $pg_highlight,
    $pg_hide,
    $ps_cat_id, 
    $parent_id, 
    $tmp_id,
    $usr_id,
    $pg_id
    ));

我发现这需要花费很长时间才能在维护时列出表格中的所有字段，所以我有这个简短的想法来解决它，

# queury the table columns.
$sql = "
SHOW COLUMNS 
FROM root_pages
";

# use the stored connection object from the class_page_controller.php, to process the query.
$columns = $connection->fetch_all($sql);

# loop through the table columns, select the 'Field' column only, turn the field into variables, then get the variable's value from the array.
foreach($columns as $column)
{
    $$column['Field'] = set_variable($_POST,$column['Field']);
}

foreach($columns as $column)
{

    $sql = "
    UPDATE root_pages
    SET 
        ".$column['Field']." = ?
    WHERE pg_id = ?
    ";

    # use the instantiated db connection object from the init.php, to process the query
    $result = $connection->run_query($sql,array($$column['Field'],$pg_id));

}

它更短但我在这个捷径中使用了大量的循环 - 是不是很糟糕？

这是否会使服务器在处理更新时变慢？我没有看到这种方法会遇到什么问题？

Answer 1

更多查询意味着更多时间，因此如果您要单独更新每个字段（而不是一次更新一行），则需要更长时间。

此外，您可能希望对提交的值应用过滤器，以确保不会更新您不想更新的字段。

例如，如果您有一个用户表，其中列出了帐户余额：

id | user       | credit
==========================
1  | John Smith | 50

如果我可以向您的表单处理程序提交表单，因为“信用”字段会显示在SHOW COLUMNS...查询中，我可以通过一个表单向您发送POST提交内容使用$_POST['user'] = "Mike Rowe" 和 $_POST['credit'] = 9999更改我的姓名，您可以将上述内容更改为：

id | user       | credit
==========================
1  | Mike Rowe  | 9999

更新：建议的解决方案

不是相信数据库字段名称可以安全地用于处理这样的查询，为什么不拥有自己的可编辑字段数组而只是循环它们呢？

$editable_fields = array(
  'pg_url' ,
  'pg_title' ,
  ...
);

$form_values = array();
$sql_pattern = array();
foreach( $editable_fields as $k ){
  if( $k != 'pg_id'
      && isset( $_POST[$k] ) ){
    $form_values[$k] = $_POST[$k];
    // NOTE: You could use a variant on your above code here, like so
    // $form_values[$k] = set_variable( $_POST , $k );
    $sql_pattern[] = "$k = ?";
  }
}

$sql_pattern = 'UPDATE root_pages SET '.implode( ' , ' , $sql_pattern ).' WHERE pg_id = ?';

# use the instantiated db connection object from the init.php, to process the query
$result = $connection->run_query($sql_pattern,array_merge(
    $form_values ,
    $_POST['pg_id']
    ));

注意：此代码未经测试，而不是我通常操作的方式，因此请将其用作指南，而不是圣经......

更新数据库中的表行的快捷方式？

1 个答案: