使用LEFT OUTER JOIN在单个查询中联接多个表 [英] JOIN multiple tables in single query using LEFT OUTER JOIN

问题描述

我在多个表中使用LEFT OUTER JOIN遇到困难.

I'm having difficulties using the LEFT OUTER JOIN in multiple tables.

我的表是:countries，customer_info，package_types，service_types和shipping_info

到目前为止，这是我的代码:

This is my code so far:

$sql = "SELECT shipping_info.shipping_id, shipping_info.weight, shipping_info.width, shipping_info.height, shipping_info.length, shipping_info.cost, shipping_info.status, 
service_types.service, package_types.package_type, countries1.country AS fromCountry, countries2.country AS toCountry, countries3.country AS resiCountry, customer_info.name, customer_info.address
, customer_info.city, customer_info.postcode, customer_info.zipcode, customer_info.phone, customer_info.email, customer_info.country
FROM shipping_info 
LEFT OUTER JOIN service_types ON shipping_info.service_type = service_types.serviceType_id 
LEFT OUTER JOIN package_types ON shipping_info.package_type = package_types.packageType_id 
LEFT OUTER JOIN customer_info ON shipping_info.customer_id = customer_info.customer_id
LEFT OUTER JOIN countries AS countries1 ON shipping_info.from_loc = countries1.country_id 
LEFT OUTER JOIN countries AS countries2 ON shipping_info.to_loc= countries2.country_id 
LEFT OUTER JOIN countries AS countries3 ON shipping_info.to_id = countries3.country_id";

$statement = $con_db->query($sql);
$result = $statement->fetchAll();

我在最后一行遇到了一个严重错误，我相信这是因为$ result为空.但我无法找出错误.

I'm getting a fatal error in my final line and I believe that's because $result is null. But I'm unable to figure out the error.

感谢任何帮助.

推荐答案

可能是您的查询有以下手动错误:

It may be your query has following manual error:

表名或字段名不匹配

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