Example if an ID is 1213 i want show **13.
If it's a number
select '**' || substr(to_char(id),3)
from my_table
Or, if it's already a character
select '**' || substr(id,3)
from my_table
This concatenates ** onto the beginning of the string, using the Oracle concatenation operator || and removes the first two characters of the id using substr.
Here's a SQL Fiddle to demonstrate.
If you don't want to sacrifice performance too much, to mask first two characters you can use-
SQL> select regexp_replace('1213','(.)2','**') from dual; --if VARCHAR
MASKED
------------
**13
SQL> select regexp_replace(1213,'(.)2','**') from dual; --if NUMBER
MASKED
------------
**13
REGEXP_REPLACE will work alike on NUMBER and VARCHAR so you save some conversion time there.
Consecutively, you can create a Function Based Index on the regexp function operation to optimize the query like (considering you would always want to mask only first two characters of ID) -
CREATE INDEX
mask_id
ON
table_name
(regexp_replace(id,'(.)2','**'));
Related
I am having an issue with getting the last character from an Oracle CLOB column. The same SQL that works on an VARCHAR column doesn't work on a CLOB column and can't figure out why or how to make it work.
(this works in getting the last character from a VARCHAR)
select substr(COLUMN_NAME, length(COLUMN_NAME), 1) from TABLE_NAME
(when applied to a CLOB column, it doesn't return the last character.
select substr(CLOB_COLUMN, length(CLOB_COLUMN), 1) from TABLE_NAME
(Updates below)
Per Alex suggestion, I added the dump/cast and get "Typ=1 Len=1: 10" for that column. (I have no idea what that is)
Here is the SQL I was running:
set linesize 32000
select
length(COLUMN_NAME) as clob_length,
substr(trim(COLUMN_NAME), length(trim(COLUMN_NAME)) -50 ) as last_50,
SUBSTR(COLUMN_NAME, -1) as last_char,
dump(cast(substr(COLUMN_NAME, -1) as varchar2(1)))
from TABLENAME
I added the SQL I used and the results for one of my rows are:
CLOB_LENGTH: 1227
LAST_50: shall be permitted to be continued in service
LAST_CHAR:
VARCHAR2(1): Typ=1 Len=1: 10
(I am not clear as to what the last value means)
Works for my simple test case:
SQL> create table test (col clob);
Table created.
SQL> insert into test (col) values ('This is a cloB');
1 row created.
SQL> select substr(col, length(col), 1) from test;
SUBSTR(COL,LENGTH(COL),1)
--------------------------------------------------------------------------------
B
Though, it is simpler to use substr(col, -1) (take the last character):
SQL> select substr(col, -1) from test;
SUBSTR(COL,-1)
--------------------------------------------------------------------------------
B
SQL>
I added the dump/cast and get "Typ=1 Len=1: 10" for that column
As suspected from your image, your CLOB values end with new lines (character 10, which is what the dump output shows), and probably other whitespace, or perhaps line feed (character 13) if the original data came from, say, Word. That's why the 'last 50' isn't showing 50 'normal' characters - there are multiple blank lines taking up some of those positions.
If you want to ignore all of those trailing characters you can change your trim to include more characters, and apply that to both substr calls; something like:
substr(rtrim(clob_column, chr(32)||chr(9)||chr(10)||chr(13)), -1)
which will remove any combination of spaces, tabs, new lines and line feeds.
db<>fiddle showing the 50 character version now appears as a single line, and the last character is null, '.', 'n', 'e' etc.
I want to write a function that will give me the next version number for a table. The table stores the existing version on each record. For example,
I have the cat table
cats
seqid 1
name Mr Smith
version number 1.2b.3.4
How can I write a program that will be able to increment these values based on various conditions?
This is my first attempt
if v_username is not null
then v_new_nbr = substr(v_cur_nbr, 1,7)||to_number(substr(v_cur_nbr, 8,1))+1
should be 1.2b.3.5
substr(v_cur_nbr, 1,7)||to_number(substr(v_cur_nbr, 8,1))+1
This hurls ORA-01722: invalid number. The reason is a subtle one. It seems Oracle applies the concatenation operator before the additions, so effectively you're adding one to the string '1.2b.3.4'.
One solution is using a TO_CHAR function to bracket the addition with the second substring before concatenating the result with the first substring:
substr(v_cur_nbr, 1,7) || to_char(to_number(substr(v_cur_nbr, 8,1))+1)
Working demo on db<>fiddle.
Incidentally, a key like this is a bad piece of data modelling. Smart keys are dumb. They always lead to horrible SQL (as you're finding) and risk data corruption. A proper model would have separate columns for each element of the version number. We can use virtual columns to concatenate the version number for display circumstances.
create table cats(
seqid number
,name varchar2(32)
,major_ver_no1 number
,major_ver_no2 number
,variant varchar2(1)
,minor_ver_no1 number
,minor_ver_no2 number
,v_cur_nbr varchar2(16) generated always as (to_char(major_ver_no1,'FM9') ||'.'||
to_char(major_ver_no2,'FM9') ||'.'||
variant ||'.'||
to_char(minor_ver_no1,'FM9') ||'.'||
to_char(minor_ver_no2,'FM9') ) );
So the set-up is a bit of a nause but incrementing the version numbers is a piece of cake.
update cats
set major_ver_no1 = major_ver_no1 +1
, major_ver_no2 = 0
, variant = 'a';
There's a db<>fiddle for that too.
Try searching mask for TO_NUMBER to be able to get the decimal number, this small example might help:
CREATE TABLE tmp_table (version varchar2(100));
INSERT INTO tmp_table(version) VALUES ('1.2b.3.4');
DECLARE
mainVersion NUMBER;
subVersion NUMBER;
currentVersion VARCHAR2(100);
BEGIN
SELECT version INTO currentVersion FROM tmp_table;
mainVersion := TO_NUMBER(SUBSTR(currentVersion,1,3),'9.9') + 0.1;
subVersion := TO_NUMBER(SUBSTR(currentVersion,6,3),'9.9') + 1.1;
UPDATE tmp_table SET version = (mainVersion||'b.'||subVersion);
END;
Am working with an Oracle 11g db in which I need to run a query that returns all rows with values in a specific format.
I.e., I need to find all rows with a value like 'abc1234'. The actual values aren't important....what I need is to find all rows with the first 3 characters being alpha and the subsequent 4 characters all being numeric.
Any input would be much appreciated.
Might not be exact since I don't have an Oracle server handy to test but something like this should get you started in the right direction:
SELECT * FROM your_table WHERE REGEXP_LIKE(your_column, '([a-z]\3[0123456789]\4', 'i')
This will check all rows in your table where the specified column has any alphabet character A to Z three times followed by 4 numbers and return that list. The 'i' at the end just says ignore case on the alphabet part. You can choose to not have that option if you so wish.
Here are a couple links as well with more information on the regexp_like syntax:
Oracle SQL - REGEXP_LIKE contains characters other than a-z or A-Z
https://docs.oracle.com/cd/B28359_01/server.111/b28286/conditions007.htm#SQLRF00501
Try it this will work definitely:
Let's take a sample example:
For example, create a sample table
CREATE TABLE bob (
empno VARCHAR2(10) NOT NULL,
ename VARCHAR2(15) NOT NULL,
ssn VARCHAR2(10) NOT NULL);
Insert data into that table
Insert into bob ( empno,ename,ssn) values ('abC0123458','zXe5378023','0pl4783202');
Insert into bob ( empno,ename,ssn) values ('0123abcdef','a12dldfddd','Rns0101010');
Query to select the all the columns
select * from bob
where length(trim(translate(substr(empno,1,3),'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',' '))) IS NULL
AND
length(trim(translate(substr(empno,4,4),'0123456789',' '))) IS NULL;
To do the same thing on multiple columns use union operator
select * from bob
where length(trim(translate(substr(empno,1,3),'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',' '))) IS NULL
AND
length(trim(translate(substr(empno,4,4),'0123456789',' '))) IS NULL;
union
select * from bob
where length(trim(translate(substr(ename,1,3),'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ',' '))) IS NULL
AND
length(trim(translate(substr(ename,4,4),'0123456789',' '))) IS NULL;
I have a table A with single column
**TableA**
Row1
Row2
Row3
.....
I have to convert the table rows into a list and store them in variables. So that they are stored as
Row1,Row2,Row3,....,Rown
I used the listagg () function to achieve the solution.
DECLARE
tbl_list CLOB;
BEGIN
SELECT listagg (''''||Column_name||'''',',') WITHIN GROUP (ORDER BY Column_name) INTO TBL_LIST FROM TableA;
END;
This works fine if the TableA has few rows. But if the table has lots of rows I get the following error
ORA-01489: result of string concatenation is too long
Is this due to the storage limit of variable TBL_LIST? Can anyone explain me what is wrong. And is there an alternate for lisagg(), to achieve the result, I want?
listagg function is limited to 4000 characters, if it exceeds 4000 character yo may get an error ORA-01489: result of string concatenation is too long
You can use XMLAGG which is not limited to 4000 char.
SELECT
RTRIM(XMLAGG(XMLELEMENT(E,''''||Column_name||'''',',').EXTRACT('//text()')
ORDER BY Column_name).GetClobVal(),',')
from TableA;
you can refer this question: How to tweak LISTAGG to support more than 4000 character in select query?
If you expect the result of aggregation to be more than 4000 bytes? If so, you could potentially create a user-defined aggregate function that returns a CLOB rather than a VARCHAR2. If you don't expect the result to exceed 4000 bytes there is probably something wrong with the way you've specified the aggregate.
Please refer to the "https://oracle-base.com/articles/misc/string-aggregation-techniques" for user defined aggregation.
My goal is to execute a query (SELECT), fetch results and output them as text. Query is given as a parameter and can be e.g. select * from t.
I use OCIStmtPrepare and OCIStmtExecute, then I can describe columns of the query by OCIParamGet and series of OCIAttrGet. Suppose I get OCI_ATTR_DATA_TYPE = 12 (DATE) for one of the columns. Then OCI_ATTR_DATA_SIZE = 7 -- this is size of internal DATE representation.
I want to get this DATE as text, with respect to currect NLS settings. For that I use OCIDefineByPos with dty = SQLT_STR. It works alright, but I also need to supply a buffer for fetching. The question is: what size of buffer do I need?
Evidently it depends on NLS_DATE_FORMAT. I believe that Oracle knows this value:
SQL> create table x as select to_char(sysdate) d from dual;
Table created.
SQL> select value from nls_session_parameters where parameter='NLS_DATE_FORMAT';
VALUE
----------------------------------------
DD.MM.RR
SQL> select data_length from dba_tab_columns where table_name='X';
DATA_LENGTH
-----------
8
This is the exact length. Only when date format is masked from Oracle (by a function, for example), it uses absolute maximum (?) value of 75:
SQL> create or replace function get_date_format return varchar2 is
2 begin
3 return 'DD.MM.RR';
4 end;
5 /
Function created.
SQL> create table x as select to_char(sysdate,get_date_format) d from dual;
Table created.
SQL> select data_length from dba_tab_columns where table_name='X';
DATA_LENGTH
-----------
75
All said above applies to NUMBER as well.
So, is it possible to get length of text representation of a column in OCI?
The maximum buffer size for any date is 75. The maximum buffer size for any number is 42.
I hope that helps.
You can determine needed buffer size by calling OCIAttrGet for OCI_ATTR_DISP_SIZE attribute. It returns 40 for NUMBER, 75 for DATE, N for VARCHAR2(N). Add 1 byte for Null-termination and you good to go.
Yes - the trick is that in C, a string is really a pointer to a character array, so you would say char* mystring = OCIStringPtr(envhp, x); where x is a pointer to an OCIString, which you can get back by connecting with OCI_OBJECT set and asking for a SQLT_VST instead of an SQLT_STR. The actual memory for the string is allocated for you in the global env by OCI behind the scenes.