關鍵字組附近的語法不正確

Question

您好，我在寫一個SQL查詢，但是在GROUP BY的行上出現語法錯誤。 可能是什么問題。

SELECT au_lname, au_fname, t.title_id
from authors As a INNER JOIN
titleauthor As ta On a.au_id = ta.au_id INNER JOIN
titles As t On t.title_id = ta.title_id
ORDER BY au_lname, au_fname
GROUP BY au_lname

Answer 1

將GROUP BY放在ORDER BY之前。 另外，select中包含的所有字段必須在GROUP BY語句中，或者在聚合函數中。

嘗試這個：

SELECT au_lname, au_fname, t.title_id
from authors As a INNER JOIN
titleauthor As ta On a.au_id = ta.au_id INNER JOIN
titles As t On t.title_id = ta.title_id
GROUP BY au_lname, au_fname, t.title_id
ORDER BY au_lname, au_fname

如果您只是想消除重復的結果，也可以使用關鍵字DISTINCT：

SELECT DISTINCT au_lname, au_fname, t.title_id
from authors As a INNER JOIN
titleauthor As ta On a.au_id = ta.au_id INNER JOIN
titles As t On t.title_id = ta.title_id
ORDER BY au_lname, au_fname

Answer 2

select語句的一般語法是

SELECT select_list
[INTO new_table_]
FROM table_source
[WHERE search_condition]
[GROUP BY group_by_expression]
[HAVING search_condition]
[ORDER BY order_expression [ASC | DESC] ;

所以你的情況

SELECT au_lname, au_fname, t.title_id
from authors As a INNER JOIN
titleauthor As ta On a.au_id = ta.au_id INNER JOIN
titles As t On t.title_id = ta.title_id
GROUP BY au_lname
ORDER BY au_lname, au_fname