oracle sql:如果存在则更新否则插入

问题描述

可能的重复:
Oracle:如何 UPSERT(更新或插入表?)

我有一个表，如果记录已经存在，则必须修改其中的记录，否则必须插入新记录.Oracle sql 不接受IF EXISTS，否则我会做一个if - update - else - insert 查询.我看过 MERGE 但它只适用于多个表.我该怎么办?

I have a table in which a record has to be modified if it already exists else a new record has to be inserted. Oracle sql doesnt accept IF EXISTS, otherwise I would have done an if - update - else - insert query. I've looked at MERGE but it only works for multiple tables. What do i do?

推荐答案

MERGE 不需要多表"，但它确实需要一个查询作为源.这样的事情应该可以工作:

MERGE doesn't need "multiple tables", but it does need a query as the source. Something like this should work:

MERGE INTO mytable d
USING (SELECT 1 id, 'x' name from dual) s
ON (d.id = s.id)
WHEN MATCHED THEN UPDATE SET d.name = s.name
WHEN NOT MATCHED THEN INSERT (id, name) VALUES (s.id, s.name);

或者，您可以在 PL/SQL 中执行此操作:

Alternatively you can do this in PL/SQL:

BEGIN
  INSERT INTO mytable (id, name) VALUES (1, 'x');
EXCEPTION
  WHEN DUP_VAL_ON_INDEX THEN
    UPDATE mytable
    SET    name = 'x'
    WHERE id = 1;
END;

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