Single Table MySQL Pivot with Dynamic Column - mysql

Question

I want to transform row of mysql table to column, through mysql pivot table
My input table.
My input table which has data in below format.
Area Status User
-----------------------
1 Active user1
1 Failed user2
1 Success user4
2 Active user2
2 Failed user3
2 Success user4
My Desired Output Format is below
Status user1 user2 user3 user4
-----------------------------------------
Active 1 1 0 0
Failed 0 1 1 0
Success 0 0 0 2
Since i do not know the exact number of users i want to pivot it through dynamic column only.

Answer 1

in your case, if you have a separate user table, you can easily make a Cartesian Product between your user table and status table, and make pivoting.. if you need further helps let me know..
have look on one of my following blog post about a pivoting schenerio for sales report, I am using a dynamic calendar table to produce Cartesian Product with Order Category table..
Sample Pivoting and Cartesian Product

Answer 2

I have another runnable example for you, from
product_id supplier_id number price
p1 s1 2 2.12
p1 s2 3 3.12
p2 s1 4 4.12
to
product_id supplier_id1 supplier_id2 number1 number2 price1 price2
p1 s1 s2 2 3 2.12 3.12
p2 s1 NULL 4 NULL 4.12 NULL
here the "supplier_id" is dynamic, it could be one little data set from a 1 million big set.so there could be supplier1,or supplier99,or supplier999,depends on whats in the source table.
first, lets create the source table:
CREATE TABLE test
(
product_id varchar(10),
supplier_id varchar(10),
number int(11),
price decimal(10,2)
);
INSERT INTO test (product_id, supplier_id, number, price) VALUES ('p1', 's1', 2, 2.12);
INSERT INTO test (product_id, supplier_id, number, price) VALUES ('p1', 's2', 3, 3.12);
INSERT INTO test (product_id, supplier_id, number, price) VALUES ('p2', 's1', 4, 4.12);
I don't think one select will do it, so the temp table and column are needed, this code is what you need:
DROP TABLE IF EXISTS final_data;
DROP TABLE IF EXISTS temp_data;
CREATE TEMPORARY TABLE temp_data
SELECT
product_id,
IF(#productid = product_id, #rownum := #rownum + 1, #rownum := 1) seller_number,
#productid := product_id,
supplier_id,
number,
price
FROM
test
CROSS JOIN (SELECT #rownum := 0) r
CROSS JOIN (SELECT #productid:="") n
ORDER BY
product_id ASC;
ALTER TABLE temp_data ADD PRIMARY KEY(product_id, seller_number);
ALTER TABLE temp_data ADD INDEX (seller_number);
#Dynamic Pivot starts via prepared statements
#Step 1: Dynamily create colum names for sql
#Field supplier_id
SET #sql = NULL;
SELECT
GROUP_CONCAT(DISTINCT
CONCAT(
' MAX(IF( seller_number= ''',
seller_number,
''', supplier_id, NULL)) AS ',
CONCAT("supplier_id", seller_number)
)
) INTO #sql
FROM temp_data;
#Field number
SELECT
CONCAT(#sql, ', ',
GROUP_CONCAT(DISTINCT
CONCAT(
' MAX(IF( seller_number= ''',
seller_number,
''', number, NULL)) AS ',
CONCAT("number", seller_number)
)
) )INTO #sql
FROM temp_data;
#Field price
SELECT
CONCAT(#sql, ', ',
GROUP_CONCAT(DISTINCT
CONCAT(
' MAX(IF( seller_number= ''',
seller_number,
''', price, NULL)) AS ',
CONCAT("price", seller_number)
)
) )INTO #sql
FROM temp_data;
#Step 2: Add fields to group by query
SET #sql = CONCAT(' create table final_data as (SELECT
product_id,
', #sql, '
FROM
temp_data
GROUP BY
product_id) ');
PREPARE stmt FROM #sql;
EXECUTE stmt;
DROP TABLE IF EXISTS temp_data;