MySQL支持位图索引吗?语法是什么?
mysql> CREATE BITMAP INDEX ON tb1(num);
ERROR 1064 (42000): You have an error in your SQL syntax; check the manual that
corresponds to your MySQL server version for the right syntax to use near 'BITMA
P INDEX ON tb1(num)' at line 1
表结构:
+-------------+----------+------+-----+---------+----------------+
| Field | Type | Null | Key | Default | Extra |
+-------------+----------+------+-----+---------+----------------+
| id | int(11) | NO | PRI | NULL | auto_increment |
| total | int(11) |
我有以下问题:
select from `table` where `a`>0 order by `b` desc limit 0, 10
select from `table` where `a`<0 order by `b` desc limit 0, 10
我要他们尽可能快地跑。现在的问题是什么是最好的解决方案?
创建a索引,b 创建a多index索引,b为b创建多index索引,a创建多index索引
我猜使用多色指数会得到最好的结果.但列的正确顺序是什么?MySQL将首先匹配列a,然后匹配b,还是首先匹配b,然后匹配a
谢谢
目前,我有一个MYSQL查询正在执行中。我需要在查询中的两个字段上创建索引:cancel和complete。执行此操作的最佳方法是什么? SELECT* FROM table WHERE cancel != 'CANCEL' AND complete IN ('COMPLETE','TAKEN_BACK')
如果MySQL中不存在索引,是否有创建索引的方法?
MySQL不支持明显的格式:
CREATE INDEX IF NOT EXISTS index_name ON table(column)
ERROR 1064 (42000): You have an error in your SQL syntax;...
MySQL版本(mysql -V)为5.1.48,但我认为MySQL在其所有版本中都缺乏CREATE INDEX IF NOT EXIST能力。
只有在MySQL中不存在索引的情况下,创建索引的正确方法是什么?
我得到了这个错误:
Notice: Undefined index: kolebro in /Applications/MAMP/htdocs/includes.php on line 12
function.php
public function User_Details($uid)
{
$username = mysql_real_escape_string($uid);
$query = mysql_query("SELECT uid, username, sansiti, kolebro AS full_name FROM users WHERE uid =