Re: Excluding values with numbers
Date: Wed, 30 Dec 2009 05:31:11 -0800 (PST)
Message-ID: <92f72abb-3a28-4f40-822c-431b928acf2b_at_o28g2000yqh.googlegroups.com>
On Dec 29, 11:54 am, Pankaj <harpreet.n..._at_gmail.com> wrote:
> Greetings,
>
> I am currently using Oracle9i Enterprise Edition Release 9.2.0.4.0. I
> have a table with following data
>
> Table 1 (Sample data)
> a12345
> A123423
> g13452
> G452323
> h34423
> r34323
> b23232
> n232323
>
> I am currently using this as a subquery in one of the query. As per a
> new request I have to now exclude all values which start with h, b or
> n followed by numeric values.
>
> So end result the subquery should give me is
>
> Table 1 (Sample data)
> a12345
> A123423
> g13452
> G452323
> r34323
>
> I am little stumped on this for now. Could not get it right in my
> query. Can anyone please advise here. Let me know if any more
> information is needed from my side.
>
> Note: The starting character in all values can sometimes in "lower
> case" or sometimes in "upper case".
>
> TIA
I agree with Joel's comments. Let's see if there is a hard way to do this.
CREATE TABLE T10(HOMEWORK VARCHAR2(20));
INSERT INTO T10 VALUES ('a12345');
INSERT INTO T10 VALUES ('A123423');
INSERT INTO T10 VALUES ('g13452');
INSERT INTO T10 VALUES ('G452323');
INSERT INTO T10 VALUES ('h34423');
INSERT INTO T10 VALUES ('r34323');
INSERT INTO T10 VALUES ('b23232');
INSERT INTO T10 VALUES ('n232323');
INSERT INTO T10 VALUES ('NB151517');
INSERT INTO T10 VALUES ('C0151517');
INSERT INTO T10 VALUES ('f9151517');
INSERT INTO T10 VALUES ('HE4423');
COMMIT; Note that I added a couple of extra rows just for fun.
Let's look at the ASCII values of the first and second characters:
SELECT
HOMEWORK,
ASCII(SUBSTR(HOMEWORK,1,1)) ASC_VAL1,
ASCII(SUBSTR(HOMEWORK,2,1)) ASC_VAL2
FROM
T10;
HOMEWORK ASC_VAL1 ASC_VAL2
---------- ---------- ----------
a12345 97 49 A123423 65 49 g13452 103 49 G452323 71 52 h34423 104 51 r34323 114 51 b23232 98 50 n232323 110 50 NB151517 78 66 C0151517 67 48 f9151517 102 57 HE4423 72 69
OK, I see the ones that we want to exclude, let's build a matrix:
SELECT
HOMEWORK,
ASCII(SUBSTR(HOMEWORK,1,1)) ASC_VAL1, ASCII(SUBSTR(HOMEWORK,2,1)) ASC_VAL2, DECODE(ASCII(SUBSTR(HOMEWORK,1,1)),
104,1,72,1,66,1,98,1,78,1,110,1,0) IS_EXC1, DECODE(SIGN(ASCII(SUBSTR(HOMEWORK,2,1))-47),1,DECODE(SIGN(ASCII (SUBSTR(HOMEWORK,2,1))-58),-1,1,0),0) IS_EXC2 FROM
T10;
HOMEWORK ASC_VAL1 ASC_VAL2 IS_EXC1 IS_EXC2 ---------- ---------- ---------- ---------- ----------
a12345 97 49 0 1 A123423 65 49 0 1 g13452 103 49 0 1 G452323 71 52 0 1 h34423 104 51 1 1 r34323 114 51 0 1 b23232 98 50 1 1 n232323 110 50 1 1 NB151517 78 66 1 0 C0151517 67 48 0 1 f9151517 102 57 0 1 HE4423 72 69 1 0
If there is a 1 in both of the right-most columns, then the row should
be eliminated. What is the easiest way to tell if there is a 1 in
both columns? Multiply the column values together, and if we receive
a product of 1 then the row should be excluded:
SELECT
*
FROM
(SELECT
HOMEWORK,
ASCII(SUBSTR(HOMEWORK,1,1)) ASC_VAL1,
ASCII(SUBSTR(HOMEWORK,2,1)) ASC_VAL2,
DECODE(ASCII(SUBSTR(HOMEWORK,1,1)),
104,1,72,1,66,1,98,1,78,1,110,1,0) IS_EXC1, DECODE(SIGN(ASCII(SUBSTR(HOMEWORK,2,1))-47),1,DECODE(SIGN(ASCII (SUBSTR(HOMEWORK,2,1))-58),-1,1,0),0) IS_EXC2 FROM
T10)
WHERE
IS_EXC1*IS_EXC2<>1;
HOMEWORK ASC_VAL1 ASC_VAL2 IS_EXC1 IS_EXC2 ---------- ---------- ---------- ---------- ----------
a12345 97 49 0 1 A123423 65 49 0 1 g13452 103 49 0 1 G452323 71 52 0 1 r34323 114 51 0 1 NB151517 78 66 1 0 C0151517 67 48 0 1 f9151517 102 57 0 1 HE4423 72 69 1 0
Something tells me you want to do it the easy way. See if you can do
anything with these functions:
REGEXP_INSTR
http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/functions129.htm
REGEXP_SUBSTR
http://download.oracle.com/docs/cd/B19306_01/server.102/b14200/functions131.htm
*Always* post the DDL and DML to re-create your problem, and show us what you have tried previously.
Charles Hooper
Co-author of "Expert Oracle Practices: Oracle Database Administration
from the Oak Table"
http://hoopercharles.wordpress.com/
IT Manager/Oracle DBA
K&M Machine-Fabricating, Inc.
Received on Wed Dec 30 2009 - 07:31:11 CST