使用來自另一個表的數據使用sql'like'命令刪除行

Question

我試圖從表中刪除行（“lovalarm”），其中字段（“pointid”）就像許多字符串中的任何一個。

目前我手動輸入它們但是我需要能夠擁有超過100,000個選項的列表。

我的想法是有一個表（“lovdata”）包含所有可能的字符串並運行查詢來刪除其中字段“喜歡”其他表中的任何字符串的行。

任何人都可以指出我是否/如何以這種方式使用？

非常感謝，Cap

Answer 1

確定你可以加入LIKE運算符：

DELETE FROM lovalarm a 
 WHERE EXISTS (SELECT NULL 
                 FROM lovdata d 
                WHERE a.pointid LIKE d.pointid)

lovdata.pointid列可能包含通配符，請考慮：

SQL> CREATE TABLE lovalarm AS
  2  SELECT 'AA' pointid FROM dual
  3  UNION ALL SELECT 'AB' FROM dual
  4  UNION ALL SELECT 'AC' FROM dual
  5  UNION ALL SELECT 'BA' FROM dual
  6  UNION ALL SELECT 'BB' FROM dual
  7  UNION ALL SELECT 'BC' FROM dual;    

Table created

SQL> --# suppose that you want to remove all entries that start
  2  --# with A or end with C
  3  CREATE TABLE lovdata AS
  4  SELECT 'A%' pointid FROM dual
  5  UNION ALL SELECT '%C' FROM dual;

Table created

SQL> DELETE FROM lovalarm a
  2   WHERE EXISTS (SELECT NULL
  3                   FROM lovdata d
  4                  WHERE a.pointid LIKE d.pointid);

4 rows deleted

SQL> select * from lovalarm;

POINTID
-------
BA
BB

Answer 2

只需使用子查詢，如下所示：

DELETE 
  FROM lovalarm
 WHERE pointid IN (SELECT mystring FROM lovdata)

編輯：剛剛注意到LIKE是必需的，所以IN不會起作用，因為這將完全匹配。 我會留在這里作為參考，因為文森特已經添加了正確的查詢。

Answer 3

這是％concatenations的示例

CREATE TABLE LOVALARM(POINTID VARCHAR2(50) ,TXT VARCHAR2(50));
create table deleteThese(deleteStringList varchar2(50));
/
INSERT INTO LOVALARM(POINTID, TXT) VALUES('abc def','1');
INSERT INTO LOVALARM(POINTID, TXT) VALUES('def','2');
INSERT INTO LOVALARM(POINTID, TXT) VALUES('abc','3');
INSERT INTO LOVALARM(POINTID, TXT) VALUES('efd','4');
INSERT INTO LOVALARM(POINTID, TXT) VALUES('abb','5');
INSERT INTO LOVALARM(POINTID, TXT) VALUES('efd bbb','6');
INSERT INTO LOVALARM(POINTID, TXT) VALUES('abb ccc','7');
INSERT INTO LOVALARM(POINTID, TXT) VALUES('abbbccc','8');


INSERT INTO DELETETHESE(DELETESTRINGLIST) VALUES('abc');
INSERT INTO DELETETHESE(DELETESTRINGLIST) VALUES('bbb');

COMMIT;
/

DELETE LOVALARM 
 where exists(
            SELECT NULL
              FROM DELETETHESE
             where LOVALARM.pointid like '%' || dELETETHESE.DELETESTRINGLIST  || '%'
        );

select * from LOVALARM;

POINTID                                            TXT                                                
-------------------------------------------------- -----
def                                                2                                                  
efd                                                4                                                  
ABB                                                5                                                  
abb ccc                                            7