删除给定特殊字符之前的所有字符 [Oracle SQL]

Question

my oracle table has a column with these data:

ROW_ID	FILE_NAME
1	ZASWEFFT%Contract V1.pdf
2	ZZZZxxxx12%Contract 03.12.14.pdf

I need to remove everything before and including the % character, which would give me:

ROW_ID	FILE_NAME
1	Contract V1.pdf
2	Contract 03.12.14.pdf

I found this similar question I changed it to fit my need and the select statement works:

SELECT SUBSTR(value, INSTR(value, '%')+1) invalue
  FROM (SELECT FILE_NAME value FROM SFDC.PROJECT_ATT));

result:

INVALUE
Contract V1.pdf
Contract 03.12.14.pdf

But I'm not able to transform this into an update statement. My last try was:

UPDATE SIEBEL.S_PROJ_ATT T1
   SET T1.FILE_NAME =
       (SELECT SUBSTR(value,
                      INSTR(value,
                            '%') + 1) invalue
          FROM (SELECT T2.FILE_NAME value
                  FROM SIEBEL.S_PROJ_ATT T2
                 WHERE T1.ROW_ID = T2.ROW_ID))

Oracle says the syntax is rubbish: ORA-00904: "T1"."ID": invalid identifier

Answer 1

You don't need the subqueries; you can just do:

update s_proj_att
set file_name = substr(file_name, instr(file_name, '%') + 1)
where instr(file_name, '%') > 0;

The where clause stops it trying to update any file names without the *% at the start.

db<>fiddle demo

The question you linked to is using a subquery - or line view - to generate the value from a string literal. You don't need to do that here, as you already have the column value.

Answer 2

you made it too complicted

CREATE TABLE S_PROJ_ATT ( ROW_ID INTEGER, FILE_NAME VARCHAR(32) );

 INSERT INTO S_PROJ_ATT (ROW_ID, FILE_NAME) VALUES ('1', 'ZASWEFFT%Contract V1.pdf');

 INSERT INTO S_PROJ_ATT (ROW_ID, FILE_NAME) VALUES ('2', 'ZZZZxxxx12%Contract 03.12.14.pdf');

 UPDATE S_PROJ_ATT SET FILE_NAME = SUBSTR(FILE_NAME, INSTR(FILE_NAME, '%')+1)

2 rows affected

SELECT * FROM S_PROJ_ATT

 ROW_ID |  FILE_NAME -----: |:-------------------- 1 | Contract V1.pdf 2 | Contract 03.12.14.pdf

db<>fiddle here