MYSQL 错误代码 1248 每个派生 table 必须有自己的别名

Question

MYSQL Error code 1248 Every derived table must have it's own alias

select supplier_id, supplier_name, strong_answers from 
(select campaign_suppliers.id supplier_id, campaign_suppliers.supplier_name supplier_name, 
count(case when supplier_answers.binary_answer is not null 
or supplier_answers.value_answer is not null then 1 end) strong_answers 
from supplier_answers join campaign_suppliers on (supplier_answers.supplier_id = campaign_suppliers.id) 
where supplier_answers.campaign_id = 1 group by campaign_suppliers.id, campaign_suppliers.supplier_name 
having count(case when supplier_answers.binary_answer is not null 
or supplier_answers.value_answer is not null then 1 end) >=  
(select count(distinct supplier_answers.question_index) from supplier_answers where campaign_id = 1)) 
where strong_answers >= (select count(distinct supplier_answers.question_index) from supplier_answers where campaign_id = 1)

Answer 1

您需要 from ( ... ) t 的 table 名称别名，请参阅下面的 // <---- 符号

select t.supplier_id, t.supplier_name, t.strong_answers from (
    select campaign_suppliers.id supplier_id, campaign_suppliers.supplier_name supplier_name, 
    count(case when supplier_answers.binary_answer is not null 
      or supplier_answers.value_answer is not null then 1 end) strong_answers 
from supplier_answers join campaign_suppliers on (supplier_answers.supplier_id = campaign_suppliers.id) 
where supplier_answers.campaign_id = 1 group by campaign_suppliers.id, campaign_suppliers.supplier_name 
having count(case when supplier_answers.binary_answer is not null 
or supplier_answers.value_answer is not null then 1 end) >=  
(select count(distinct supplier_answers.question_index) 
        from supplier_answers where campaign_id = 1)) t //<----  here you need  a table name eg: t
where t.strong_answers >= (select count(distinct supplier_answers.question_index) from supplier_answers where campaign_id = 1)