mysql字符串group_concat给我一个错误

Question

我在尝试这个sql时遇到错误...

SELECT customers.customers_first_name GROUP_CONCAT(customers_groups.customers_hash SEPARATOR '') 
FROM customers INNER JOIN customers_groups ON (customers.hash = customers_groups.customers_hash) 
GROUP BY customers.customers_entry_date



CUSTOMERS DATABASE
`customers_id`, 
`customers_first_name`, 
`customers_surname`, 
`customers_telephone`, 
`customers_email`, 
`customers_telephone_active`, 
`customers_email_active`, 
`client_type`, 
`customers_hash`, 
`customers_entry_date`

CUSTOMERS_GROUPS
`groups_hash`
`customers_hash

Answer 1

理想情况下，您应该发布带​​有问题的错误消息，但请检查以下解决方案。

SELECT customers.customers_first_name, GROUP_CONCAT(customers_groups.customers_hash SEPARATOR '') 
FROM customers INNER JOIN customers_groups ON (customers.hash = customers_groups.customers_hash) 
GROUP BY customers.customers_entry_date

SELECT customers.customers_first_name ，

  在GROUP_CONCAT

之前的select语句中缺少

“，”