将部分复制的新记录插入同一张表

Question

我对SQLite还是很陌生，并试图做一些看起来很简单但无法正常工作的事情。

我想在具有相同OwnerID但数据略有不同的表（部分副本）中插入一条新记录，因此插入记录数据；

2，55，newdata，DARLTY

原始记录数据在哪里；

1，55，originaldata，DARLTY

问题是我一直在'OwnerID'附近：语法错误。我想在将原始记录值插入新记录之前，需要以某种方式将其转换为变量，但是如何呢？

这就是我拥有的明显有缺陷的TIA

    INSERT INTO MyTable
 NULL AS KeyID, OwnerID AS OwnerID, 'newdata' AS Field2, Field3 AS Field3
 WHERE Field3 LIKE '%DARL%'
 AND Field3 <> 'DARLINGTON'
;

Answer 1

您缺少 SELECT 和 FROM 关键字。

因此您的查询应该/应该是：-

INSERT INTO mytable 
    SELECT null AS keyid,ownerid AS ownerid,field2 AS field2,field3 AS field3 
    FROM mytable WHERE field3 LIKE '%DARLTY%' AND field3 <> 'DARLINGTON';

虽然稍微简单一些：-

INSERT INTO mytable (ownerid,field2,field3) 
    SELECT ownerid,field2,field3 
    FROM mytable WHERE field3 LIKE '%DARLTY%' AND field3 <> 'DARLINGTON';

会完全一样。

例如以下（为方便起见，在表名中添加了 x ）：-

DROP TABLE IF EXISTS mytablex ;
CREATE TABLE IF NOT EXISTS mytablex (keyid INTEGER PRIMARY KEY,ownerid INTEGER,  field2 TEXT, field3 TEXT);
INSERT INTO mytablex VALUES(1,55,'newdata','DARLTY'); -- Original value
INSERT INTO mytablex (ownerid,field2,field3) 
    SELECT ownerid,field2,field3 
    FROM mytablex WHERE field3 LIKE '%DARLTY%' AND field3 <> 'DARLINGTON';
SELECT * FROM mytablex;

结果：-

但是，当心，如果您随后运行插入操作，则会插入更多行，例如再次使用以下命令：-

INSERT INTO mytablex (ownerid,field2,field3) 
    SELECT ownerid,field2,field3 
    FROM mytablex WHERE field3 LIKE '%DARLTY%' AND field3 <> 'DARLINGTON';
SELECT * FROM mytablex;

将导致：-

如果第三次运行，则：-

为消除此类重复，您不妨考虑使用：-

INSERT INTO mytablex (ownerid,field2,field3) SELECT ownerid,field2,field3 
    FROM mytablex 
        WHERE field3 LIKE '%DARLTY%' 
            AND field3 <> 'DARLINGTON' 
            AND (
                SELECT count() FROM mytablex WHERE field3 LIKE '%DARLTY%' AND field3 <> 'DARLINGTON'
                 ) = 1;