Question

我正在尝试从我的数据库中获取一些数据。

有点像这样

组

groups_id，groups_name，groups_description，groups_active，groups_hash，groups_entry_date，user_id，groups_email ，groups_sms

CUSTOMERS_GROUPS

customers_hash，groups_hash

客户

customers_id，customers_first_name，customers_surname，customers_telephone，customers_email，customers_telephone_active，customers_email_active，client_type ，customers_hash，customers_entry_date

我想以concat形式使用customers.groups_hash和groups.groups_name。这是我的尝试......

SELECT * , GROUP_CONCAT( DISTINCT customers_groups.groups_hash
SEPARATOR '/' ) , GROUP_CONCAT( groups.groups_name
SEPARATOR '/' )
FROM customers
INNER JOIN customers_groups ON ( customers.customers_hash = customers_groups.customers_hash )
LEFT JOIN groups ON ( customers_groups.customers_hash = groups.groups_hash )
WHERE groups.groups_active ='1' GROUP BY customers.customers_entry_date

但是它让我回归零......

Answer 1

问题是你的where子句。它必须是on子句的一部分：

SELECT * , GROUP_CONCAT( DISTINCT customers_groups.groups_hash
SEPARATOR '/' ) , GROUP_CONCAT( groups.groups_name
SEPARATOR '/' )
FROM customers
INNER JOIN customers_groups ON ( customers.customers_hash = customers_groups.customers_hash )
LEFT JOIN groups ON ( customers_groups.customers_hash = groups.groups_hash ) AND groups.groups_active ='1' 
GROUP BY customers.customers_entry_date

Answer 2

问题在于：

LEFT JOIN groups ON ( customers_groups.customers_hash = groups.groups_hash )

应该是

LEFT JOIN groups ON ( customers_groups.groups_hash = groups.groups_hash )

（虽然目前还不清楚哈希实际代表什么，以及为什么没有桥表连接表格的ID。我在评论部分向你的请求提出了这个问题。）

sql字符串无法正确

2 个答案: