我没有收到任何错误,因为这只是一个小问题.
EXPLAIN
SELECT
a.nid,
a.title,
a.uid,
b.parent,
b.weight,
c.name,
d.value
FROM table1 AS a INNER JOIN table2 AS b ON a.vid = b.vid AND a.status = 1
INNER JOIN table3 AS c ON c.uid = a.uid
INNER JOIN table4 AS d ON d.content_id = a.nid AND d.value_type = 'percent' AND d.function = 'average'
当我查看哪些表被引用时,一切都很好,但是从table4中它应该只选择"value"字段,我得到一个ALL被称为...
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE a ref PRIMARY,vid,status,uid,node_status_type,nid status 4 const 1
1 SIMPLE b eq_ref PRIMARY PRIMARY 4 …