EXPLAIN
SELECT * FROM test_askcomment WHERE cid IN(1,2,3) ORDER BY dateline DESC;
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE test_askcomment ALL PRIMARY NULL NULL NULL 3 Using where; Using filesort
1 回答
尝试索引你正在使用where子句或选择coloumns的coloumns