计算类别中的文章数

Question

This code only shows categories with articles in them. I want to show all categories. Pls help.

$query = "SELECT C.id, C.jcat_name,COUNT(A.catid) AS catid FROM jt_categories C INNER JOIN jt_articles A ON C.id = A.catid GROUP BY C.id";

Answer 1

Change INNER JOIN for LEFT JOIN in your query.

INNER JOIN looks explicitely for the join in the data

Answer 2

用左外部连接替换内部连接

Answer 3

change to left join

 SELECT C.id, C.jcat_name,COUNT(A.catid) AS catid FROM jt_categories C 
LEFT JOIN jt_articles A ON C.id = A.catid GROUP BY C.id

Answer 4

将INNER JOIN更改为LEFT JOIN 。

Answer 5

Did u try LEFT JOIN ? bc. (i think) in second table u have NULL articles for some categories.