问题描述
我有一个从大型数据库中提取的结果集:
I have a result set I pull from a large database:
$result = mysql_query($sql);
我一次遍历此记录集以提取特定的数据位，并使用while($row = mysql_fetch_array($result))获得平均值.在页面的稍后，我想再次遍历这个相同的记录集并输出所有内容-但是由于我之前使用了记录集，因此我的第二个循环什么都不返回.
I loop through this recordset once to pull specific bits of data and get averages using while($row = mysql_fetch_array($result)). Later in the page, I want to loop through this same recordset again and output everything - but because I used the recordset earlier, my second loop returns nothing.
我终于通过遍历第二个相同的记录集($result2 = mysql_query($sql);)来解决这个问题，但是我讨厌两次进行相同的SQL调用.有什么方法可以多次遍历同一数据集吗?
I finally hacked around this by looping through a second identical recordset ($result2 = mysql_query($sql);), but I hate to make the same SQL call twice. Any way I can loop through the same dataset multiple times?
推荐答案
使用:
mysql_data_seek($result, 0);
您已经获得了免费"，因为它已经被缓冲了.
You get this "free", since it's already buffered.
另外，您可以使用 mysql_unbuffered_query .
As a separate note, you can explicitly do an unbuffered query with mysql_unbuffered_query.
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