MySQL 语句未按预期返回

Question

我有 3 张 table :

1. 供应商: ID、姓名、地址、郊区、州、电话、电子邮件、已删除

2. 客户: ID、姓名、地址、郊区、州、电话、电子邮件、已删除

3. 认可的供应商: id、supplier_id、customer_id

我想显示所有供应商并“标记”那些已在 ACCREDITED_SUPPLIERS 中链接的供应商...

这是我的声明:

SELECT SQL_CALC_FOUND_ROWS s.id, s.name, s.suburb, s.state, s.phone, s.email, s.deleted, 
IF( ac.customer_id =  '220', 1, 0 ) AS accredited
FROM suppliers s 
LEFT OUTER JOIN accredited_suppliers ac ON ac.supplier_id = s.id 
WHERE s.deleted='0'  
ORDER BY s.name

此语句仅返回 10 个“标记”行

由于某种原因，它莫名其妙地丢失了 3 行!

SELECT * 
FROM  `accredited_suppliers` 
WHERE  `customer_id` =  '220'

返回:13 行

我上面的说法正确吗？我发出的信息正确吗？

Answer 1

你不只是想要:

select
  s.id AS supplier_id,
  IF(a.supplier_id IS NULL, 0, 1) AS accredited
from
  SUPPLIERS s
    left join
      ACCREDITED_SUPPLIERS a
    ON
      s.id = a.supplier_id AND
      a.customer_id = 220;