吾生也有涯，而知也无涯
mysql> explain select(select count(*) from article where user_id=1),(select sum(collect_num) from article where user_id=1),(select sum(collect_num) from article where user_id=1);+
|>
+
|1 | PRIMARY | NULL | NULL| NULL | NULL | NULL | NULL | NULL | No tables used |
|4 | SUBQUERY | article | index | user_id_like_num_collect_num | user_id_like_num_collect_num | 104 | NULL | 3047331 | Using where; Using index |
|3 | SUBQUERY | article | index | user_id_like_num_collect_num | user_id_like_num_collect_num | 104 | NULL | 3047331 | Using where; Using index |
|2 | SUBQUERY | article | index | user_id_like_num_collect_num | user_id_like_num_collect_num | 104 | NULL | 3047331 | Using where; Using index |
+
页:
[1]