MySql引发运行此sql的ProgrammingError
SELECT parents.uuid AS parents_uuid, children.uuid AS children_uuid,
children.parent_uuid AS children_parent_uuid,
count(*) OVER (PARTITION BY parents.uuid) AS children_count
FROM parents, children
WHERE children.parent_uuid = parents.uuid ORDER BY children_count DESC
我在mysql中有以下功能
CREATE FUNCTION `get_project_uuid`(project_kee varchar(400)) RETURNS varchar(50) CHARSET utf8
BEGIN
declare v_project_uuid varchar(50);
select project_uuid into v_project_uuid from projects where scope='PRJ' and kee=project_kee;
RETURN v_project_uuid;
END
当我直接从mysql命令提示
在Java中使用空构造函数可以吗?例如,当从MySQL数据库加载数据时,我希望执行以下操作:
ResultSet set = statement.executeQuery();
while (set.next()) {
Faction faction = new Faction();
faction.setId(UUID.fromString(set.getString("id")));
faction.setName(set.getString("name"));
}
因为我已经有了一个派系类的构造函数,
public Faction(
我有一个用php编写的简单的登录脚本,当我运行它时,它应该比较来自彼此的2个密码散列。这是im使用的代码;
$UUID = $_POST['UUID'];
$pass = $_POST['pass'];
// finds the same user where the uuid is the same as the one given in the post request
$query = "SELECT * FROM users WHERE UUID = '$UUID'";
$result = mysql_query($q
我们希望测试mysql数据库中用于主键/索引的序列/bigint vs UUID(VERSION-4) VS UUID(version-7)的性能。对于mysql来说是个新手,很难找到一种简单的方法来轻松地创建数据卷,测试性能,并且“解释分析”在这里似乎也不起作用。基本上想做一些类似于下面的代码在postgres.Can中所做的事情,请在这里指导我?
(UUID Version-4是默认的随机UUID版本,Version-7是时间戳排序的UUID,它比随机的UUID更有顺序,因此在缓存方面更好)。希望以某种方式在mysql中生成这些数据并进行测试。
下面的代码在postgres中工作得很好,我
在MySQL数据库中,我需要将一些UUID列(BINARY(16))转换为VARCHAR。我想以规范的形式,而不是以字节的形式来转换它们。为了清晰起见,使用小写和连字符,而不是0xHEXADECIMAL格式。
在Postgres,这就足够了:
ALTER TABLE my_table
ALTER COLUMN my_uuid_column
TYPE VARCHAR(36);
MySQL等效值返回一个错误:
ALTER TABLE my_table
MODIFY COLUMN my_uuid_column
TYPE VARCHAR(36);
ERROR 1366 (HY000)
我试图在insert查询中使用SELECT UUID()。这是我的诡计
INSERT INTO `posts`(`post_id`, `user_id`, `content`, `time`) VALUES (SELECT uuid(),1,'my content',mytime)
我搞错了a comma or a closing bracket was expected mysql near uuid
我目前正在尝试进行一个PHP调用,以便在用户第一次登陆页面时接收由以下代码块设置的cookie
if (empty($_COOKIE["uuid"])) {
$uuid = uniqid(); // or use a real UUID
setcookie("info", $uuid, $thisAid, $thisSubID, $thisURL, time()+30*24*60*60, "/");
}
else {
$uuid = $_COOKIE["uuid"];
foreach($_COOKIE as $name =>