Question

我正在尝试向表中插入一些条目，并且在该条目已经存在时不执行任何操作。我的主键包含多个列（event_timestamp，device_id，path，message_id）。

当我尝试类似JDBC中的以下语句时：

MERGE INTO events dest
                    USING ( SELECT event_timestamp, device_id, path, message_id from events) src
                    ON (dest.event_timestamp = src.event_timestamp
                    and dest.device_id = src.device_id
                    and dest.path = src.path
                    and dest.message_id = src.message_id)
                    WHEN NOT MATCHED THEN
                    INSERT (event_timestamp, device_id, path, message_id, text, direction, speed, net, gross)
                    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)

什么也没插入。

使用普通语句：

INSERT (event_timestamp, device_id, path, message_id, text, direction, speed, net, gross) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)

所有内容均插入无问题。

我还尝试更改select语句以从DUAL中进行选择，而不是像这样的事件：

MERGE INTO events dest
                    "USING ( SELECT event_timestamp, device_id, path, message_id from DUAL) src
                    ON (dest.event_timestamp = src.event_timestamp
                    and dest.device_id = src.device_id 
                    and dest.path = src.path
                    and dest.message_id = src.message_id)
                    WHEN NOT MATCHED THEN
                    INSERT (event_timestamp, device_id, path, message_id, text, direction, speed, net, gross)
                    VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)

但随后我得到了例外：ORA-00904: invalid identifier

我该怎么做才能使其正常工作？

Answer 1

您要传递的新值应该是SELECT FROM dual子句中USING的一部分

MERGE INTO events dest USING (
     SELECT ? as event_timestamp,
            ? as device_id,
            ? as path,
            ? as message_id
     FROM dual
)
src ON (
      dest.event_timestamp = src.event_timestamp 
      AND dest.device_id = src.device_id 
      AND dest.path = src.path 
      AND dest.message_id = src.message_id
)
WHEN NOT MATCHED THEN INSERT (
     event_timestamp,
     device_id,
     path,
     message_id,
     text,
     direction,
     speed,
     net,
     gross ) VALUES (?,?,?,?,?,?,?,?,?);

也可以使用像这样的普通INSERT INTO .. SELECT。

INSERT INTO events (
     event_timestamp,
     device_id,
     path,
     message_id,
     text,
     direction,
     speed,
     net,
     gross ) 
SELECT ?,?,?,?,?,?,?,?,? FROM DUAL
WHERE NOT EXISTS ( select 1 from events d WHERE  
          d.event_timestamp  = ? 
      AND d.device_id        = ?
      AND d.path             = ?
      AND d.message_id       = ?
      );

Demo

使用复合主键合并到表中

1 个答案: