光标循环；如何仅在循环开始/结束时执行某项操作 1 次？
我的 Oracle 程序之一中有以下内容，我使用它来生成 XML
-- v_client_addons is set to '' to avoid null error
OPEN C_CLIENT_ADDONS;
LOOP
FETCH C_CLIENT_ADDONS INTO CLIENT_ADDONS;
EXIT WHEN C_CLIENT_ADDONS%NOTFOUND;
BEGIN
v_client_addons := v_client_addons || CLIENT_ADDONS.XML_DATA;
END;
END LOOP;
CLOSE C_CLIENT_ADDONS;
-- Do something later with v_client_addons
循环应该遍历我的光标并挑选出所有要显示的 XML 值，例如：
<add-on name="some addon"/>
<add-on name="another addon"/>
我想要实现的是此循环内有一个 XML 开始/结束标记，因此我将得到以下输出
<addons>
<add-on name="some addon"/>
<add-on name="another addon"/>
</addons>
如何在每行后面不使用
I've got the following in one of my Oracle procedures, I'm using it to generate XML
-- v_client_addons is set to '' to avoid null error
OPEN C_CLIENT_ADDONS;
LOOP
FETCH C_CLIENT_ADDONS INTO CLIENT_ADDONS;
EXIT WHEN C_CLIENT_ADDONS%NOTFOUND;
BEGIN
v_client_addons := v_client_addons || CLIENT_ADDONS.XML_DATA;
END;
END LOOP;
CLOSE C_CLIENT_ADDONS;
-- Do something later with v_client_addons
The loop should go through my cursor and pick out all of the XML values to display, such as :
<add-on name="some addon"/>
<add-on name="another addon"/>
What I would like to achieve is to have an XML start/end tag inside this loop, so I would have the following output
<addons>
<add-on name="some addon"/>
<add-on name="another addon"/>
</addons>
How can I do this without having the <addons> tag after every line? If there are no addons in the cursor (cursor is empty), then I would like to skip this part enitrely
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检查 v_client_addons 的长度。如果它大于 0，则您实际上附加了一些内容。然后创建父标签及其子标签，否则忽略它。
check the length of v_client_addons. If it is greater than 0, you actually appened something. Then create you parent tag with its children, else just ignore it.
使用 SQL 生成整个 XML，而不是循环游标怎么样？
How about using SQL to generate the entire XML, instead of looping over a cursor?