explain select * from user where id in (1,2,3)explain select name from user where id in (1,2,3) explain select id from user where id in (1,2,3)
Mysql显示类型是索引。
status, date_added);我写了以下两个查询,上面的两个索引可以完全满足这两个查询,但MySQL将where放在额外的列中。mysql> EXPLAIN SELECT cat_id FROM articles USE INDEX (cat_list_INX) WHERE cat_id=158 AND status=2 ORDER------+---------------+-----------
----------------+------+-----+---------------------+-----------------------------+1 row in set (0.00 sec)
上面的索引是使用的,但下面的索引不使用。mysql> explain select runtime_id from tabl
我正在尝试用PHP显示我的表,数据库中的t2d_10,chr10。我的表有5列,分别是rs1、rs2、rs3、rs4、rs5。这是我的密码: mysql_select_db($db, $connection) or die ("Unable to select database!");
$query = "SELECT * FROM t2d_10";
/