MySQL>汇总为一个查询(包括Google Maps) [英] MySQL > sum up into a single query (incl. google maps)

问题描述

此问题是@Vincent Savard对我的一个问题发表评论的后续报道.

This Q is posted as a follow up to a comment on one of my Qs by @Vincent Savard.

目前，我正在尝试(取得了一些成功-谷歌地图XML请求在60秒后达到超时)将(漂亮的)大型表中的数据拆分为许多较小的表-以及对其进行转换/修改/等操作.苍蝇.对于此任务，我在以下示例附近使用php:

Currently I'm trying (with some success - hitting timeout after 60 sec. for google-maps XML requests) to split data from a (pretty) large table into lots of smaller tables - plus converting/modifying/etc them on the fly. For this task I'm using php close to the following example:

// The following happens inside some functions.
// The main table has some "groups" of content.
// fn_a creates the new small tables
"
CREATE TABLE {$small_table_a}
    col_group_a_id int UNSIGNED NOT NULL AUTO_INCREMENT,
    col_group_a_fname tinytext,
    col_group_a_lname tinytext,
    col_group_a_valA tinytext,
    col_group_a_valB tinytext,
    col_group_a_address tinytext,
    col_group_a_lat decimal(9,3),
    col_group_a_lng decimal(9,3),
    PRIMARY KEY  (id)
"
"
CREATE TABLE {$small_table_b}
    col_group_b_id int UNSIGNED NOT NULL AUTO_INCREMENT,
    col_group_b_fname tinytext,
    col_group_b_lname tinytext,
    col_group_b_valA tinytext,
    col_group_b_valB tinytext,
    col_group_b_address tinytext,
    col_group_b_lat decimal(9,3),
    col_group_b_lng decimal(9,3),
    PRIMARY KEY  (id)
"

// fn_b loads the content from the big table, modifies it and saves it row per row into the small tables
$sql = "
SELECT *
FROM {$big_table}
"
foreach ( $sql as $data )
{
    $id = $data->id;

    $group_a_fname = $data->group_a_fname;
    $group_a_lname = $data->group_a_lname;
    $group_a_lname = "{$group_a_fname}, {$group_a_lname}";
    $group_a_valA = $data->group_a_valA ? $data->group_a_valA : '-';
    $group_a_valA = $data->group_a_valB ? $data->group_a_valB : 'none';
    $group_a_valA = $data->group_a_address;

    $group_b_fname = $data->group_b_fname;
    $group_b_lname = $data->group_b_lname;
    $group_b_name = "{$group_b_fname}, {$group_b_lname}";
    $group_b_valA = $data->group_b_valA ? $data->group_b_valA : '/';
    $group_b_valA = $data->group_b_valB ? "€ {$data->group_b_valB}" : null;

    "
    INSERT INTO {$small_table_a} ... VALUES ...
    "
}

// fn_c pulls in data from the small tables, asks the google map API for lat & lng and _should_ update the small table

$sql = "
SELECT *
FROM {$small_table_a}
"
foreach ( $sql as $data )
{
    $output['id'] = $data->id;

    $address = urlencode( $data->address );
    $url = "http://maps.google.com/maps/api/geocode/xml?address={$address}&sensor=false";
    $content = file_get_contents( $url );
    $file_data = new SimpleXMLElement( $content );
    $file_data = $file_data->result ? $file_data->result : null;
    if ( ! $file_data ) 
        continue;
    $location = $file_data->geometry->location;
    $output['lat'] = (string) $location->lat;
    $output['lng'] = (string) $location->lng;
}
foreach ( $output as $data )
{
    "
    UPDATE {$table}
    SET lat=SET lat={$data['lat']}, lng={$data['lng']}
    WHERE id=$data['id']
}

问题:我如何在一个查询中做到这一点?或者如何减少数据库查询?当今天超出地理编码限制时，如何在不中断查询构建的情况下将lat/lng添加到表中-我不想仅仅因为超出限制而放弃所有内容.

Question: How could I do this in one query? Or how could I reduce DB-queries? And how would I add the lat/lng to the tables without interrupting the query building when my geocoding limit was exceeded for today - I don't want to drop everything just because I've gone over my limit.

谢谢！

注意:该示例是我脑海中手写的.那里可能有失败.

推荐答案

我们需要知道您的foreach循环中的INSERT INTO查询是什么，因为这可以汇总为一个查询.基本上，这是一个主意:

We need to know what the INSERT INTO query is in you foreach loop, because this is the one that can be summed into one query. Basically, here is the idea:

INSERT INTO {$small_table} -- you can specify which columns to fill,
                           -- i.e. INSERT INTO table (col_a, col_b)
    SELECT group_a_fname, group_a_lname, 
           group_a_valA, group_a_valB, 
           group_a_address, group_b_fname, 
           group_b_lname, group_b_valA, group_b_valB -- etc
    FROM {$big_table};

很显然，您必须调整查询来满足您的需求.您只需要了解其背后的想法即可:您可以使用SELECT查询插入行.

Obviously, you'll have to adapt the query to fill your needs. You just need to grasp the idea behind it : you can insert rows with a SELECT query.

UPDATE查询是不同的，因为您必须依赖外部数据(网站).我认为在一个查询中没有一种简单的方法可以做到这一点，但是我可能是错的.

The UPDATE query is different because you have to rely on external data (a website). I don't think there is an easy way to do it in one query, but I may be wrong.

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