我有一个查询
$arr_status = array('1' => '申请中', '2'=>'处理中', '3' => '已发货', '4' => '已退款');
$lotterylist = array();
$sqltext = "SELECT* from {$tablepre}exchange WHERE uid = '$discuz_uid' ORDER BY exchangetime DESC LIMIT $start_limit, $tpp";
$query = $db->query($ ......
SELECT * from alarms where id in (select resource_id from res_products where product=22)
这个语句在mysql中为什么不能执行?我的mysql数据库是5.0.27版本的!
如果实在不行那么该用个什么语句代替效率更高呢?
引用
试试
SQL code
select a.*
from alarms a inner join res_products b on a.id=b.resource_ ......
Java code:
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: The last packet successfully received from the server was51093 seconds ago.The last packet sent successfully to the server was 51093 seconds ago, which is longer than the server configured value of 'wait_timeout'. You should co ......
把图片存入到mysql中:
DateTime dt = (DateTime)para[0];
string plateNo = (string)para[1];
byte[] photo = (byte[])para[2];
string sqlString = "insert into table1(Time,PlateNo,PlateImg) VALUES(?dt,?plateNo, ......
mysql备份或查询的时候。。如果设置的缓存内存不够,是报错。还是把缓存里面的数据输出在来接受新的内容?
应该是报错。最好自己试一下,那样感受会更深一些。
其实你自己想一下就明白了。
假设你在一台物理内存只有 128M的机器上查一个大表(3G),结果会报错吗?
引用
其实你自己想一下就明白了。
假设你在一台 ......
String sql = "select resourceSn,aclState&1,aclState&2,aclState&4,aclState&8,aclTriState from acl ";
我用的是mysql数据库,我想问下为什么它提示sql语句有错。它的错误是这样的 ,好像认识不出& 符号,不是mysql支持这样查询吗?
错误信息:
unexpected char: '&am ......