Information_schema.columns in the query - sql

Question

I need to pull the data from custom columns in all tables which have "custom1, custom2, custom3....." columns.
Declare #TableName varchar(max)
set #TableName = 'RandomTable';
with main as
(
select distinct
infos.COLUMN_NAME, infos.TABLE_NAME
from
INFORMATION_SCHEMA.COLUMNS infos
where
infos.TABLE_NAME = #TableName
and infos.COLUMN_NAME like 'Custom%%'
)
This query returns the list of custom columns in any table I specify in the parameter. Any idea how to use that in the query so I can get all the data from the RandomTable.Custom%% columns?
Any idea? I'm loosing the plot on it.

Answer 1

Following incomudro idea and guessing you are using SQL Server you could do something like this:
DECLARE
#TableName VARCHAR(MAX)
,#ColumnName VARCHAR(MAX)
,#SQLQuery VARCHAR(MAX)
,#FirstFlag BIT
SET #TableName = 'TEST'
SELECT
COL.COLUMN_NAME
INTO ##CUSTOM_COL
FROM INFORMATION_SCHEMA.COLUMNS COL
WHERE 1 = 1
AND COLUMN_NAME LIKE 'CUSTOM__'
AND TABLE_NAME = #TableName
DECLARE CUR_CUSTOM_COL CURSOR FOR
SELECT * FROM ##CUSTOM_COL
OPEN CUR_CUSTOM_COL
FETCH NEXT FROM CUR_CUSTOM_COL INTO #ColumnName
SET #FirstFlag = 1
SET #SQLQuery = 'SELECT *'
WHILE ##FETCH_STATUS = 0
BEGIN
IF #FirstFlag = 0
BEGIN
SET #SQLQuery = #SQLQuery + ', '
END
SET #SQLQuery = #SQLQuery + #ColumnName
SET #FirstFlag = 0
FETCH NEXT FROM CUR_CUSTOM_COL INTO #ColumnName
END
CLOSE CUR_CUSTOM_COL
DEALLOCATE CUR_CUSTOM_COL
SET #SQLQuery = #SQLQuery + ' FROM ' + #TableName
EXEC(#SQLQuery)
I saved my workspace in this fiddle. Unfortunaly it doesnt work there as intendet, but it should in your SQL Client(or I did a little typing mistake). With some little modifications you could not only display the custom columns from 1 specified table but from all tables. Also you could, besides selecting it, insert the ouput from the custom columns in temp tables.