我需要找到每个作者的最新帖子,然后对结果进行分组,这样我每个作者只会发一个最新的帖子.
SELECT wp_posts.* FROM wp_posts
WHERE wp_posts.post_status='publish'
AND wp_posts.post_type='post'
GROUP BY wp_posts.post_author
ORDER BY wp_posts.post_date DESC
这是正确地对输出进行分组,因此我每个作者只获得一个帖子,但是在分组后将结果排序,而不是在选择之前.
如何使用JPA运行如下所示的查询.(它适用于纯SQL)
SELECT t
FROM table t
WHERE
(
CASE WHEN (( ... subquery ... ) IS NULL)
THEN (t.category IS NULL)
ELSE (t.viewId = :viewId)
END
)
我得到了MismatchedTokenException在IS
THEN (t.category IS NULL)
可能吗？或者我需要重写这个查询？
我有一个XHTML页面,其中有四个文本框
<h:column >
<f:facet name="header">
<h:outputText value="Start Date" />
</f:facet>
<h:inputText id="startDate" value="#{sampleVO.startDate}" />
</h:column>
<h:column >
<f:facet name="header">
<h:outputText value="End Date" />
</f:facet>
<h:inputText id="endDate" value="#{sampleVO.endDate}" />
</h:column>
<h:column >
<f:facet name="header">
<h:outputText value="Start Date" />
</f:facet>
<h:inputText id="startDate1" value="#{sampleVO.startDate}" />
</h:column>
<h:column >
<f:facet name="header">
<h:outputText value="End Date" />
</f:facet>
<h:inputText id="endDate1" value="#{sampleVO.endDate}" />
</h:column>
我需要在开始日期和结束日期进行验证.如果用户在id ="startDate"&id ="endDate"中输入一些开始和结束日期,请说开始日期:"01/01/2012"(1jan)和结束日期:01/31/2012并且如果用户输入某些日期在id ="startDate1"和id ="endDate1"id ="startDate1"应始终大于id ="endDate",即日期范围不应重叠
public class SampleServiceimpl implements SampleService {
private List<SampleVO> listOfSample;
//this function gets called when clicked on …CREATE TABLE em_user
(
user_id character(10),
last_attempt integer,
last_unsuccessfull_login timestamp with time zone,
is_locked boolean DEFAULT false);
UPDATE em_user
SET is_locked = TRUE
WHERE last_attempt >3 AND last_unsuccessfull_login=last_unsuccessfull_login+'2 minutes';
我想在postgresql中1小时后更新我的表.
最近我发现我的MySQL数据库中有太多连接:
mysql> show status like 'Conn%';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| Connections | 39 |
+---------------+-------+
1 row in set (0.00 sec)
mysql> show full processlist;
+----+-------+-----------+--------+---------+------+-------+-----------------------+
| Id | User | Host | db | Command | Time | State | Info |
+----+-------+-----------+--------+---------+------+-------+-----------------------+
| 38 | enrmr | localhost | cakedb | Query | 0 | NULL | show full processlist |
+----+-------+-----------+--------+---------+------+-------+-----------------------+
我最近安装了CakePHP,每次刷新主页面(F5)时,连接数都会增加一个.另外如果我再次重启mysql连接数仍然是39.
我的netstat输出
netstat -n -a | grep 3306
tcp 0 0 127.0.0.1:3306 …我在Netbeans中开发了这样的JSF-Page
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html">
<h:head>
<title>Facelet Title</title>
...
<script type="text/javascript" language="JavaScript">
function drawShape()
{
...
var length = shapeCollection.length;
for (var i = 0; i < length; i++)
{
...
}
}
</script>
</h:head>
<h:body onload="drawShape();">
<canvas id="myDrawing" width="500" height="500">
<p>Your browser doesn't support canvas.</p>
</canvas>
</h:body>
</html>
现在我在这部分出现错误 for (var i = 0; i < length; i++)
如果我更换<与!=它的工作原理
我该如何避免这个问题？
java ×2
mysql ×2
cakephp ×1
connection ×1
eclipselink ×1
group-by ×1
javascript ×1
jpa ×1
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php ×1
postgresql ×1
sql-order-by ×1
wordpress ×1