dynamic columns in oracle using sql - sql

Question

I have following example of table. Thera can be unlimited branch and customers. I need group this branches and count their customers, then show it's with different columns.
BRANCHNAME CUSTOMERNO
100 1001010
100 1001011
103 1001012
104 1001013
104 1001014
104 1001015
105 1001016
105 1001017
106 1001018
Note that there can be unlimited branch and customers, the query must work not only this case.
In this case the accepted result is:
100 103 104 105 106
2 1 3 2 1
Example SQL DATA
select '100' BranchName,'1001010' CustomerNo from dual UNION ALL
select '100' BranchName,'1001011' CustomerNo from dual UNION ALL
select '103' BranchName,'1001012' CustomerNo from dual UNION ALL
select '104' BranchName,'1001013' CustomerNo from dual UNION ALL
select '104' BranchName,'1001014' CustomerNo from dual UNION ALL
select '104' BranchName,'1001015' CustomerNo from dual UNION ALL
select '105' BranchName,'1001016' CustomerNo from dual UNION ALL
select '105' BranchName,'1001017' CustomerNo from dual UNION ALL
select '106' BranchName,'1001018' CustomerNo from dual

Answer 1

I think it is possible, though quite complicated, to write a pipelined table function that returns a variable structure. Your pipeline table function will use the Oracle Data Cartridge interface and the magic of the AnyDataSet type to return a dynamic structure at runtime. You can then use that in subsequent SQL statements as if it was a table, i.e.
SELECT *
FROM TABLE( your_pipelined_function( p_1, p_2 ));
A couple more references that discuss the same sample implementation
Dynamic SQL Pivoting
The Implementing the Interface Approach section of the Oracle Data Cartridge Developer's Guide
Method4. After downloading and installing the open source PL/SQL code, here is a complete implementation:
--Create sample table.
create table branch_data as
select '100' BranchName,'1001010' CustomerNo from dual UNION ALL
select '100' BranchName,'1001011' CustomerNo from dual UNION ALL
select '103' BranchName,'1001012' CustomerNo from dual UNION ALL
select '104' BranchName,'1001013' CustomerNo from dual UNION ALL
select '104' BranchName,'1001014' CustomerNo from dual UNION ALL
select '104' BranchName,'1001015' CustomerNo from dual UNION ALL
select '105' BranchName,'1001016' CustomerNo from dual UNION ALL
select '105' BranchName,'1001017' CustomerNo from dual UNION ALL
select '106' BranchName,'1001018' CustomerNo from dual;
--Create a dynamic pivot in SQL.
select *
from table(method4.dynamic_query(
q'[
--Create a select statement
select
--The SELECT:
'select'||chr(10)||
--The column list:
listagg(
replace(q'!sum(case when BranchName = '#BRANCH_NAME#' then 1 else 0 end) "#BRANCH_NAME#"!', '#BRANCH_NAME#', BranchName)
, ','||chr(10)) within group (order by BranchName)||chr(10)||
--The FROM:
'from branch_data' v_sql
from
(
--Distinct BranchNames.
select distinct BranchName
from branch_data
)
]'
));

Answer 2

If you just want to report the results somewhere, you may use a cursor for the select statement:
select branchname, count(*) from test group by branchname order by branchname asc;
Looping through the cursor you may get your values.
here is my sample:
declare
v_b varchar2(1000);
v_t varchar2(1000);
begin
for i in (select branchname, count(*) total from test group by branchname order by branchname asc)
loop
v_b := v_b || i.branchname || ' ';
v_t := v_t || i.total || ' ';
end loop;
dbms_output.put_line(v_b);
dbms_output.put_line(v_t);
end;

Answer 3

This will get it in rows (rather than columns):
SELECT branchname,
COUNT( DISTINCT customerno ) AS customers
FROM your_table
GROUP BY branchname;
(Note: you can omit the DISTINCT keyword if there will never be repeats of the branchname, customerno pair.)
Without knowing what the branch names are you are could only do a dynamic pivot.
It would be much simpler to take the output of the above query (in row format) and transpose it in whatever front-end you are using to access the database.
From comments:
I need a report in this format, and don't want write some application , wants to do with sql for easily export to excell in such format
No, you don't need it in column format in SQL. You can put it into excel in row format and then use excel's TRANSPOSE function to convert it (very simply) to columns without having to implement a complicated dynamic SQL solution.

Answer 4

What about this solution. Without no table creation, just set the v_sql parameter.
SET SERVEROUTPUT ON SIZE 100000
DECLARE
v_cursor sys_refcursor;
CURSOR get_columns
IS
SELECT EXTRACTVALUE (t2.COLUMN_VALUE, 'node()') VALUE
FROM (SELECT *
FROM TABLE (XMLSEQUENCE (v_cursor))) t1,
TABLE (XMLSEQUENCE (EXTRACT (t1.COLUMN_VALUE, '/ROW/node()'))) t2;
v_column VARCHAR2 (1000);
v_value VARCHAR2 (1000);
v_counter NUMBER (3) := 0;
v_sql VARCHAR2 (4000);
BEGIN
v_sql :=
'SELECT branchname, COUNT (DISTINCT customerno) AS customers'
|| ' FROM (SELECT 100 branchname, 1001010 customerno'
|| ' FROM DUAL'
|| ' UNION ALL'
|| ' SELECT 100 branchname, 1001011 customerno'
|| ' FROM DUAL'
|| ' UNION ALL'
|| ' SELECT 103 branchname, 1001012 customerno'
|| ' FROM DUAL'
|| ' UNION ALL'
|| ' SELECT 104 branchname, 1001013 customerno'
|| ' FROM DUAL'
|| ' UNION ALL'
|| ' SELECT 104 branchname, 1001014 customerno'
|| ' FROM DUAL'
|| ' UNION ALL'
|| ' SELECT 104 branchname, 1001015 customerno'
|| ' FROM DUAL'
|| ' UNION ALL'
|| ' SELECT 105 branchname, 1001016 customerno'
|| ' FROM DUAL'
|| ' UNION ALL'
|| ' SELECT 105 branchname, 1001017 customerno'
|| ' FROM DUAL'
|| ' UNION ALL'
|| ' SELECT 106 branchname, 1001018 customerno'
|| ' FROM DUAL)'
|| ' GROUP BY branchname';
OPEN v_cursor FOR v_sql;
FOR v_record IN get_columns
LOOP
IF v_counter = 0
THEN
v_column := v_column || v_record.VALUE || ' ';
v_counter := 1;
ELSIF v_counter = 1
THEN
v_value := v_value || v_record.VALUE || ' ';
v_counter := 0;
END IF;
END LOOP;
DBMS_OUTPUT.put_line (v_column);
DBMS_OUTPUT.put_line (v_value);
END;
/
And the output is
100 105 104 103 106
2 2 3 1 1

Answer 5

with src as
(select '100' BranchName,'1001010' CustomerNo from dual UNION ALL
select '100' BranchName,'1001011' CustomerNo from dual UNION ALL
select '103' BranchName,'1001012' CustomerNo from dual UNION ALL
select '104' BranchName,'1001013' CustomerNo from dual UNION ALL
select '104' BranchName,'1001014' CustomerNo from dual UNION ALL
select '104' BranchName,'1001015' CustomerNo from dual UNION ALL
select '105' BranchName,'1001016' CustomerNo from dual UNION ALL
select '105' BranchName,'1001017' CustomerNo from dual UNION ALL
select '106' BranchName,'1001018' CustomerNo from dual )
SELECT * FROM
(select BranchName from src)
PIVOT XML
(COUNT(*) FOR (BranchName)
IN
(SELECT DISTINCT BranchName FROM SRC))
This query gives the output in xml format. The whole xml data will be contained in the field that the query results(The query has only single row-sinlge column output). The next step is to parse the xml data and display it in tabular form.

Answer 6

You can use this selection:
SELECT branchname, count(*)
FROM test
GROUP BY branchname
In general it is not professional to use selection for every number in branchname.