Suppose if the table name is ABC_XYZ_123. I want to extract the integer values after _.
The output should be integer values after _.
In the above case, the output should be 123.
I have used the below sql query.
select from table_name like 'XXX_%';
But I am not getting required output. Can anyone help me with this query.
Thanks
Using REGEXP_SUBSTR with a capture group we can try:
SELECT REGEXP_SUBSTR(name, '_(\d+)$', 1, 1, NULL, 1)
FROM yourTable;
The question is somewhat unclear:
it looks as if you're looking for table names that contain number at the end, while
query you posted suggests that you're trying to select those numbers from one of table's columns
I'll stick to
Suppose if the table name is ABC_XYZ_123
If that's so, it is the data dictionary you'll query. USER_TABLES contains that information.
Let's create that table:
SQL> create table abc_xyz_123 (id number);
Table created.
Query selects numbers at the end of table names, for all my tables that end with numbers.
SQL> select table_name,
2 regexp_substr(table_name, '\d+$') result
3 from user_tables
4 where regexp_like(table_name, '\d+$');
TABLE_NAME RESULT
-------------------- ----------
TABLE1 1
TABLE2 2
restore_point-001 001
ABC_XYZ_123 123 --> here's your table
SQL>
Apparently, I have a few of them.
Related
Could you please tell me how to compare differences between table and my select query and insert those results in separate table? My plan is to create one base table (name RESULT) by using select statement and populate it with current result set. Then next day I would like to create procedure which will going to compare same select with RESULT table, and insert differences into another table called DIFFERENCES.
Any ideas?
Thanks!
You can create the RESULT_TABLE using CTAS as follows:
CREATE TABLE RESULT_TABLE
AS SELECT ... -- YOUR QUERY
Then you can use the following procedure which calculates the difference between your query and data from RESULT_TABLE:
CREATE OR REPLACE PROCEDURE FIND_DIFF
AS
BEGIN
INSERT INTO DIFFERENCES
--data present in the query but not in RESULT_TABLE
(SELECT ... -- YOUR QUERY
MINUS
SELECT * FROM RESULT_TABLE)
UNION
--data present in the RESULT_TABLE but not in the query
(SELECT * FROM RESULT_TABLE
MINUS
SELECT ... );-- YOUR QUERY
END;
/
I have used the UNION and the difference between both of them in a different order using MINUS to insert the deleted data also in the DIFFERENCES table. If this is not the requirement then remove the query after/before the UNION according to your requirement.
-- Create a table with results from the query, and ID as primary key
create table result_t as
select id, col_1, col_2, col_3
from <some-query>;
-- Create a table with new rows, deleted rows or updated rows
create table differences_t as
select id
-- Old values
,b.col_1 as old_col_1
,b.col_2 as old_col_2
,b.col_3 as old_col_3
-- New values
,a.col_1 as new_col_1
,a.col_2 as new_col_2
,a.col_3 as new_col_3
-- Execute the query once again
from <some-query> a
-- Outer join to detect also detect new/deleted rows
full join result_t b using(id)
-- Null aware comparison
where decode(a.col_1, b.col_1, 1, 0) = 0
or decode(a.col_2, b.col_2, 1, 0) = 0
or decode(a.col_3, b.col_3, 1, 0) = 0;
SQL> create table justlike(customerid varchar(19),first_name varchar(40),last_name varchar(100),Address varchar(50),city varchar(30),pincode varchar(10),state varchar(20));
Just use:
desc <table_name>;
This will print the description of your table columns
in your case:
desc justlike;
You can always check the table definition, in case you are using Oracle, by running below query -
SELECT * FROM USER_TAB_COLS
WHERE TABLE_NAME = 'JUSTLIKE';
OR you can write a select on table itself -
SELECT * FROM JUSTLIKE;
Background : My purpose is to write an aggregate function in oracle to make a string contains number of occurrence of each element. For example "Jake:2-Tom:3-Jim:5" should means 2 times occurrence for Jake, 3 times for Tom and 5 times for Jim. So for writing a custom aggregate function I should write an object implements ODCIAggregate routines. And also a Map like data structure for counting each element occurrences. Only Map like data structure in oracle is associative array.
Problem : Unfortunately I can't know any approach to use associative arrays in object. I tried these approaches:
1 – Create a generic type for associative array and use it in object. Oracle doesn't let creating generic associative array types.
CREATE TYPE STR_MAP IS TABLE OF NUMBER INDEX BY VARCHAR2(100);
This get following error :
PLS-00355: use of pl/sql table not allowed in this context
2 – Create map like type in a package and use it in object. Oracle lets creating an associative array in a package, but doesn’t let using an 'in package type' in object. I checked all issues about grant execute on package or make a synonym for 'in package type'. But there is no way for use 'in package type' in object declaration.
P.S. 1 :
Of course we can do it for one column by nested group by. But I prefer to do it for many columns with only agg-func. It is very useful agg-func and I wonder why nobody wrote something like this before. For many columns we have limited number of distinct values, and with such an agg-func we can simply summarize all of them. For example if we had such a agg-func named ocur_count(), we can simply analyze an collection of transactions like this :
select ocur_count(trans_type), ocur_count(trans_state), ocur_count(response_code), ocur_count(something_status) from transaction;
You can use listagg and a simple group by with a count to get what you need (Note the listagg output is limited in size to 4k chars). Here I'm counting occurrences of first names, using ',' as the separator between names and ':' as the separator for count:
SQL> create table person_test
(
person_id number,
first_name varchar2(50),
last_name varchar2(50)
)
Table created.
SQL> insert into person_test values (1, 'Joe', 'Blow')
1 row created.
SQL> insert into person_test values (2, 'Joe', 'Smith')
1 row created.
SQL> insert into person_test values (3, 'Joe', 'Jones')
1 row created.
SQL> insert into person_test values (4, 'Frank', 'Rizzo')
1 row created.
SQL> insert into person_test values (4, 'Frank', 'Jones')
1 row created.
SQL> insert into person_test values (5, 'Betty', 'Boop')
1 row created.
SQL> commit
Commit complete.
SQL> -- get list of first names and counts into single string
SQL> --
SQL> -- NOTE: Beware of size limitations of listagg (4k chars if
SQL> -- used as a SQL statement I believe)
SQL> --
SQL> select listagg(person_count, ',')
within group(order by person_count) as person_agg
from (
select first_name || ':' || count(1) as person_count
from person_test
group by first_name
order by first_name
)
PERSON_AGG
--------------------------------------------------------------------------------
Betty:1,Frank:2,Joe:3
1 row selected.
NOTE: If you do run into a problem with string concatenation too long (exceeds listagg size limit), you can choose to return a CLOB using xmlagg:
-- this returns a CLOB
select rtrim(xmlagg(xmlelement(e,person_count,',').extract('//text()') order by person_count).GetClobVal(),',')
from (
select first_name || ':' || count(1) as person_count
from person_test
group by first_name
order by first_name
);
Hope that helps
EDIT:
If you want counts for multiple columns (firstname and lastname in this example), you can do:
select
typ,
listagg(cnt, ',') within group(order by cnt)
as name_agg
from (
-- FN=FirstName, LN=LastName
select 'FN' as typ, first_name || ':' || count(1) as cnt
from person_test
group by first_name
union all
select 'LN' as typ, last_name || ':' || count(1) as cnt
from person_test
group by last_name
)
group by typ;
Output:
"FN" "Betty:1,Frank:2,Joe:3"
"LN" "Blow:1,Boop:1,Jones:2,Rizzo:1,Smith:1"
I'd also note that you probably can create a custom aggregate function to do this, I just prefer to stick with built in functionality of SQL first if it can solve my problem.
I created the following table:
Create table temp.test(c1 VARCHAR2(10 BYTE));
I was trying to use CHAR_USED to determine whether the column size is in BYTES or CHARS but all I am getting back is '0 rows fetched from 1 column'. The database version i am using is Oracle 11g. Does anyone have a clue as to why it is not return the semantic length information for this table?
The query used are as follows:
select CHAR_USED from all_tab_columns where table_name='temp.test'
select CHAR_USED from all_tab_columns where table_name='test' and owner = 'temp'
Assuming that you are not using case-sensitive identifiers (which you are not and should not), object names are stored in the data dictionary in upper case. So when you query a table like all_tab_columns, you'd need to use upper-case
SELECT column_name, char_used
FROM all_tab_columns
WHERE table_name = 'TEST'
AND owner = 'TEMP'
I have two Oracle questions.
How can I set the primary key of a table when the table is made up of an object type? e.g.
CREATE TABLE object_names OF object_type
I have created a Varray type,
CREATE TYPE MULTI_TAG AS VARRAY(10) OF VARCHAR(10);
but when I try to do
SELECT p.tags.count FROM pg_photos p;
I get an invalid identifier error on the "count" part. p.tags is a MULTI_TAG, how can I get the number of elements in the MULTI_TAG?
First of all I wouldn't recommend storing data in Object tables. Objects are a great programmatic tool but querying Object tables leads to complicated SQL. I would advise storing your data in a standard relationnal model and using the objects in your procedures.
Now to answer your questions:
A primary key should be immutable, so most of the time an Object type is inappropriate for a primary key. You should define a surrogate key to reference your object.
You will have to convert the varray into a table to be able to query it from SQL
For example:
SQL> CREATE TYPE MULTI_TAG AS VARRAY(10) OF VARCHAR(10);
2 /
Type created
SQL> CREATE TABLE pg_photos (ID number, tags multi_tag);
Table created
SQL> INSERT INTO pg_photos VALUES (1, multi_tag('a','b','c'));
1 row inserted
SQL> INSERT INTO pg_photos VALUES (2, multi_tag('e','f','g'));
1 row inserted
SQL> SELECT p.id, COUNT(*)
2 FROM pg_photos p
3 CROSS JOIN TABLE(p.tags)
4 GROUP BY p.id;
ID COUNT(*)
---------- ----------
1 3
2 3
1)
A primary key is a constraint, to add constrains on object tables check this link:
http://download-west.oracle.com/docs/cd/B28359_01/appdev.111/b28371/adobjdes.htm#i452285
2)
The COUNT method can't be used in a SQL statement:
REF LINK IN COMMENTS
So in my case I had to do
SELECT p.pid AS pid, count(*) AS num_tags FROM pg_photos p, TABLE(p.tags) t2 GROUP BY p.pid;