Convert row data to new columns based on common ID value - sql

Question

I have an MS Access database for product ID list for each client ID.
Currently, the table is set up as the following:
CLI_ID || PRODUCT_ID
963506 || 49001608
968286 || 49001645
987218 || 00048038
987218 || 49001401
999999 || 9999999
999999 || 9999998
999999 || 9999997
999999 || 9999996
I would like to transpose the data to look like this:
CLI_ID || PRODUC1 || PRODUC2 || PRODUC3 || PRODUC4 ||
963506 || 49001608 ||
968286 || 49001645 ||
987218 || 00048038 || 49001401 ||
999999 || 99999999 || 99999998 || 99999997 || 99999996 ||
There are clients with more products than 4 in the example shown above so I would like the query to be expandable by counting # of product IDs in each client ID.
I took the code from ChrisPadgham's post and modified it to meet my needs...Here is what I have so far but it is not going further than PRODUC1:
TRANSFORM Last([PRODUCT_ID]) AS Details
SELECT Source_Table.CLI_ID
FROM Source_Table
GROUP BY Source_Table.CLI_ID
PIVOT "PRODUC" & (DCount("[PRODUCT_ID]","[Source_Table]", "[PRODUCT_ID]<>" &
[PRODUCT_ID] & " AND [CLI_ID]=" & [CLI_ID]) +1);
Any help would be appreciated!

Answer 1

Try adding a per client item counter to your data. Examples Found Here
It looks like your going to need to create a temp table as Access can't keep track of internal pointers when nesting the queries.
Create a temp table:
SELECT t1.CLI_ID, t1.PRODUCT_ID, (SELECT COUNT(*)
FROM Source_Table t2
WHERE t2.CLI_ID = t1.CLI_ID
AND t2.PRODUCT_ID <= t1.PRODUCT_ID
) AS PROD_COUNT INTO TEMP_CLI_PROD
FROM Source_Table AS t1
GROUP BY t1.CLI_ID, t1.PRODUCT_ID;
Then have your pivot table reference the temp table.
TRANSFORM Last(TEMP_CLI_PROD.PRODUCT_ID) AS LastOfPRODUCT_ID
SELECT TEMP_CLI_PROD.CLI_ID
FROM TEMP_CLI_PROD
GROUP BY TEMP_CLI_PROD.CLI_ID
PIVOT "PRODUCT " & TEMP_CLI_PROD.PROD_COUNT;
Output:
CLI_ID PRODUCT 1 PRODUCT 2 PRODUCT 3 PRODUCT 4
963506 49001608
968286 49001645
987218 00048038 49001401
999999 9999996 9999997 9999998 9999999

Answer 2

Jeff's answer is essentially correct in its approach, although a temporary table is not strictly required:
TRANSFORM First(PRODUCT_ID) AS whatever
SELECT CLI_ID
FROM
(
SELECT t1.CLI_ID, t1.PRODUCT_ID, 'PRODUCT_' & COUNT(*) AS XtabColumn
FROM
Source_Table AS t1
INNER JOIN
Source_Table AS t2
ON t1.CLI_ID = t2.CLI_ID
AND t1.PRODUCT_ID >= t2.PRODUCT_ID
GROUP BY t1.CLI_ID, t1.PRODUCT_ID
)
GROUP BY CLI_ID
PIVOT XtabColumn
returns
CLI_ID PRODUCT_1 PRODUCT_2 PRODUCT_3 PRODUCT_4
------ --------- --------- --------- ---------
963506 49001608
968286 49001645
987218 00048038 49001401
999999 9999996 9999997 9999998 9999999