oracle 在 COALESCE 中使用 SELECT
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Using SELECT inside COALESCE
提问by user3808188
How do I correct the following SQL code, specifically the COALESCE part?
如何更正以下 SQL 代码，特别是 COALESCE 部分？
insert into Stmt G (ID,blah,foo)
select
coalesce(SELECT ID FROM Stmt G WHERE G.CLAIMNO=C.CLNUMBER, select StmtSeq.nextval from dual),
c.blah,
d.foo
from claim c
left join d on ...;
I'm taking the ID from the Stmt table itself if the ClaimNo matches, otherwise creating a new one. Is this not allowed in SQL? How else can I write this statement?
如果 ClaimNo 匹配，我将从 Stmt 表本身获取 ID，否则创建一个新的。这在 SQL 中是不允许的吗？我还能怎么写这个声明？
I'm getting a "Missing Expression" error on the coalesce part right now.
我现在在合并部分收到“缺少表达式”错误。
回答by Patrick Hofman
You should place parenthesis around the selects:
您应该在selects周围放置括号：
coalesce( (SELECT ID FROM Stmt G WHERE G.CLAIMNO=C.CLNUMBER)
, (select StmtSeq.nextval from dual)
)
