UPSERT 用于“INSERT INTO tab SELECT * FROM another_tab"
我会怎么做UPSERT"?(INSERT OR UPDATE) 插入到 SQLite 表中时从另一个表中插入多行.
How would I do "UPSERT" (INSERT OR UPDATE) into SQLite table when inserting multiple rows from another table.
我试过了:
INSERT INTO tab_name
SELECT * FROM tmp
ON CONFLICT(id)
DO UPDATE SET
val = excluded.val;
但它给了我:
DO"附近的语法错误
实现这一目标的正确和最有效的方法是什么?
What would be the correct and the most efficient way to achieve that?
推荐答案
您可能遇到了一个名为 的记录陷阱解析歧义 :
You might have hit a documented trap called parsing ambiguity :
当 UPSERT
附加到的 INSERT
语句从 SELECT
语句中获取其值时,可能存在解析歧义.解析器可能无法判断 "ON"
关键字是否引入了 UPSERT
或者它是否是连接的 ON
子句.要解决此问题,SELECT
语句应始终包含 WHERE
子句,即使该 WHERE
子句只是 "WHERE true"
.)
When the
INSERT
statement to which theUPSERT
is attached takes its values from aSELECT
statement, there is a potential parsing ambiguity. The parser might not be able to tell if the"ON"
keyword is introducing theUPSERT
or if it is theON
clause of a join. To work around this, theSELECT
statement should always include aWHERE
clause, even if thatWHERE
clause is just"WHERE true"
.)
那么,这样效果更好吗?
So, does this work better?
INSERT INTO tab_name
SELECT * FROM tmp WHERE true
ON CONFLICT(id) DO UPDATE SET val = excluded.val;
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