Sql 在子查询中仅返回一行

我正在执行以下查询以在Laravel视图上显示这些记录

$companies = DB::select(DB::raw("SELECT (
            SELECT f.name FROM fields f WHERE f.id = (
                SELECT fc.field_id FROM c_f fc WHERE fc.company_id = c.id  
            )
        )field, c.name, c.email, (
            SELECT name as country FROM countries WHERE id = (SELECT country_id from states WHERE id = (SELECT state_id from cities WHERE id = (SELECT city_id from addresses WHERE id = c.address_id))) 
        )country,
        (
            SELECT name as state_name FROM states WHERE id = (SELECT state_id from cities WHERE id = (SELECT city_id from addresses WHERE id = c.address_id)) 
        )states, (
            SELECT name as city FROM cities WHERE id = (SELECT city_id from addresses WHERE id = c.address_id) 
        )city
        FROM companies c WHERE c.user_id = 1")); 

我对这条线有意见

SELECT name as city FROM cities WHERE id = (SELECT city_id from addresses WHERE id = c.address_id)

因为在我的数据库中有很多同名的城市，所以它抛出了一个错误，（可能与州的情况相同，但错误是在城市抛出的。在这种情况下，我试图在子查询的末尾添加限制1，但它给了我一个错误，所以我想我不能在子查询中使用限制

这就是我试图改变的

SELECT name as city FROM cities WHERE id = (SELECT city_id from addresses WHERE id = c.address_id LIMIT 1)

这就是桌子的样子

公司

地址

城市

州

国家

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我如何解决这个问题？

您没有提供示例数据和预期输出：（仍在猜测您的数据结构：

SELECT name as city 
FROM cities 
inner join addresses on addresses.city_id = cities.id 
WHERE addresses.id = c.address_id

---

您应该将整个查询编写为一个

连接

。如果它返回多行，则很容易看到重复问题的所在。请注意，根据您编写的内容，这并不是因为城市名称相同，因为您从不根据名称进行选择。如果看不到数据结构，则很难确定，但这是正确的应该很接近：

SELECT f.name AS field,
       c.name,
       c.email,
       r.name AS country,
       s.name AS states,
       m.name AS city
FROM companies c
JOIN c_f fc ON fc.company_id = c.id
JOIN fields f ON f.id = fc.field_id
JOIN addresses a ON a.id = c.address_id
JOIN cities m ON m.id = a.city_id
JOIN states s ON s.id = m.state_id
JOIN countries r ON r.id = s.country_id

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我对问题进行了编辑，以显示表的外观以及表上的一些数据，我的预期输出仅为一个城市，子查询返回多行数据reason@pinkWojak，这些都是图片（在编码中几乎总是无用的），不管怎样，代码是正确的。