我有想要更快的Mysql查询

问题描述

  $ result1  = mysql_query（  SELECT distinct city FROM postcodedb WHERE web ='ALR'ORDER BY city）或 die（mysql_error（））; 
 while（$ row1 = mysql_fetch_array（$ result1））{
  $ city  = $ row1 [ '  city']; 
  $ result  = mysql_query（  SELECT * FROM postcodedb WHERE area ='$ city'AND ='$ city'LIMIT 1）或 die（mysql_error（））; 
 while（$ row = mysql_fetch_array（$ result））{
  $ city  = $ row [ '  city']; 
} 

因此在数据库记录中看起来像这样：



id city area

1 Bromley Bromley - 我需要此记录

2 Bromley other1

3 Bromley other1

4伊尔福德伊尔福德 - 然后这一个

5伊尔福德其他1



所以我想要得到的是不同城市的列表，但对我来说重要的是我得到行ID，其中城市和地区都是一样的？



这个查询的工作原理我希望它可以工作但是有点慢，我相信有更好的方法可以达到同样的效果吗？



我希望自己清楚解释一下！





非常感谢您！



Nita

解决方案

$result1 = mysql_query("SELECT distinct city FROM postcodedb WHERE web='ALR' ORDER BY city") or die(mysql_error());
while($row1=mysql_fetch_array($result1)) {
$city = $row1['city'];
$result = mysql_query("SELECT * FROM postcodedb WHERE area='$city' AND city='$city' LIMIT 1") or die(mysql_error());
while($row=mysql_fetch_array($result)) {
$city = $row['city'];
}

So in database records look like this:

id city area
1 Bromley Bromley - i need this record
2 Bromley other1
3 Bromley other1
4 Ilford Ilford - and then this one
5 Ilford other1

So what I’m trying to get is listing of distinct cities, but important is for me is that i get row ID where both city and area are the same??

This query works as i want it to work but is a bit slow, and I believe there is a better way to achieve the same result??

I hope I explain myself clear !


Thank you very much in advance!

Nita

解决方案

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