postgresql PL/pgSQL 中的 BREAK 语句
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原文地址: http://stackoverflow.com/questions/15173194/
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BREAK statement in PL/pgSQL
提问by user1844840
How to have the breakstatement in PostgreSQL? I have the structure like this:
如何break在 PostgreSQL 中有语句？我有这样的结构：
for()
{
for()
{
if(somecondition)
break;
}
}
As per my understanding it should only break the inner forloop?
根据我的理解，它应该只打破内for循环？
回答by Erwin Brandstetter
There is no BREAK
有没有BREAK
EXITterminates the loop.CONTINUEcontinues at the next iteration of the loop.
You can attach a <<label>>to loops and add it as parameter to each of these commands. Then you terminate / continue the labeledloop. Else, it concerns the innerloop.RETURNexits from the function (so not applicable in a DOstatement).
EXIT终止循环。CONTINUE在循环的下一次迭代中继续。
您可以将 a 附加<<label>>到循环并将其作为参数添加到这些命令中的每一个。然后终止/继续标记循环。否则，它涉及内循环。RETURN从函数中退出（因此不适用于DO语句）。
All of this applies to procedural elements of PL/pgSQL, notSQL.
Code example using all three:
所有这些都适用于 PL/pgSQL 的过程元素，而不是SQL。
使用所有三个的代码示例：
回答by Fritz Lehmann-Grube
Note, that: Yes! you need the "WHEN", even if you end up (like me ;-)) with something like
请注意：是的！你需要“WHEN”，即使你最终（像我一样;-)）
LOOP
...
IF l_my_var = 'some condition' THEN
-- this is ok, bla
IF l_debug_level >= 2 THEN
RAISE NOTICE 'debug 2: skipping a duplicate %, l_my_var;
END IF;
-- do something
CONTINUE WHEN TRUE; -- https://stackoverflow.com/questions/15173194/break-statement-in-pl-pgsql
ELSE
-- do something
END IF;
...
which looks somewhat twisted with both IF and WHEN.
IF 和 WHEN 看起来都有些扭曲。
Remark to the editor: One could make the link behind "CONTINUE" more precise: https://www.postgresql.org/docs/9.6/plpgsql-control-structures.html#AEN66440
对编辑的评论：可以使“继续”后面的链接更精确：https: //www.postgresql.org/docs/9.6/plpgsql-control-structures.html#AEN66440
