How to get sum of multiple rows in a table dynamically

Question

I am trying to get the total sum from columns of a specific data type(money) for multiple tables in a database. Currently I am able to get the list of columns from specific tables but I am unable to get the sums from those columns.

This is what I have now

    use database 1 
Select + Column_Name
    From information_schema.columns
    Where TABLE_NAME = 'claimant'
    and data_type = 'money'

The result looks something like below

table_name	column_name
table_1	column_a
table_1	column_b
table_1	column_c

what I would like

table_name	column_name	total_sum
table_1	column_a	66.20
table_1	column_b	300.50
table_1	column_c	5389.42

update for @Squirrel Here is the code I have but it's still giving me issues with truncation.

{

declare @sql nvarchar(max);

select  @sql = 'with cte as (' + char(13)
            + 'select' + char(13)
            + string_agg(char(9) + quotename(column_name) + ' = sum(' + quotename(COLUMN_NAME) + ')', ',' + char(13)) + char(13)
            + 'from ' + max(quotename(table_name)) + char(13)
            + ')' + char(13)
            + 'select a.table_name, a.column_name, a.total_sum ' + char(13)
            + 'from   cte ' + char(13)
            + 'cross apply (' + char(13)
            + char(9) + 'values' + char(13)
            + string_agg(char(9) + '(''' + table_name + ''',''' + column_name  + ''',' + quotename(COLUMN_NAME) + ')', ',' + char(13)) + char(13)
            + ') a (table_name, column_name, total_sum)'
from   information_schema.columns AS A
INNER JOIN EDL01.STAGING.TABLE_DETAILS B
ON A.TABLE_NAME = B.DEST_TABLE_NAME
where  A.table_name = B.DEST_TABLE_NAME
and    data_type  = 'money'



print @sql
exec sp_executesql @sql 
}

below is the create table

CREATE TABLE [staging].[TABLE_DETAILS](
    [SOURCE_TABLE_NAME] [varchar](100) NULL,
    [DEST_TABLE_NAME] [varchar](100) NULL,
    [TYPE] [varchar](10) NULL,
    [PRIORITY] [int] NULL,
    [SOURCE_TABLE_DATABASE] [varchar](50) NULL,
    [SOURCE_TABLE_SCHEMA] [varchar](50) NULL,
    [DEST_TABLE_DATABASE] [varchar](50) NULL,
    [DEST_TABLE_SCHEMA] [varchar](50) NULL
) ON [PRIMARY]
GO

Below is part of the results

select a.table_name, a.column_name, a.total_sum 
from   cte 
cross apply (
    values
('PAYMENT','BILLEDAMOUNT',[BILLEDAMOUNT]),
    ('PAYMENT','AMOUNT',[AMOUNT]),
    ('SIMS_PAYMENT','CHECKAMOUNT',[CHECKAMOUNT]),
    ('BILLREVIEWHEADER','JURISDICTIONAMOUNT1',[JURISDICTIONAMOUNT1]),
    ('BILLREVIEWHEADER','JURISDICTIONAMOUNT2',[JURISDICTIONAMOUNT2]),
    ('BILLREVIE

Answer 1

You need to form the query dynamically and then execute it using sp_executesql or exec()

Note : char(9) is tab, char(13) is carriage return. These are added to format the query so that it is readable when you print it out for verification.

declare @sql nvarchar(max);

select @sql = 'with cte as (' + char(13)
            + 'select' + char(13)
            + string_agg(char(9) + quotename(column_name) + ' = sum(' + quotename(column_name) + ')', ',' + char(13)) + char(13)
            + 'from ' + max(quotename(table_name)) + char(13)
            + ')' + char(13)
            + 'select a.table_name, a.column_name, a.total_sum ' + char(13)
            + 'from   cte ' + char(13)
            + 'cross apply (' + char(13)
            + char(9) + 'values' + char(13)
            + string_agg(char(9) + '(''' + table_name + ''', ''' + column_name + ''',' + quotename(column_name) + ')', ',' + char(13)) + char(13)
            + ') a (table_name, column_name, total_sum)'
from   information_schema.columns
where  table_name = 'table_1'
and    data_type  = 'money'

print @sql
exec sp_executesql @sql

For your sample table, the generated dynamic query is

with cte as (
select
    [column_a] = sum([column_a]),
    [column_b] = sum([column_b]),
    [column_c] = sum([column_c])
from [table_1]
)
select a.table_name, a.column_name, a.total_sum 
from   cte 
cross apply (
    values
    ('table_1', 'column_a',[column_a]),
    ('table_1', 'column_b',[column_b]),
    ('table_1', 'column_c',[column_c])
) a (table_name, column_name, total_sum)

EDIT using a loop to iterate each table. Basically it execute above query for each of the table and insert the result into a temp table

see db<>fiddle demo

for earlier SQL Server version without string_agg(), use for xml path

select @sql  = 'with cte as (' + char(13)
             + 'select' + char(13)
             + stuff
               (
                  (
                      select ',' + quotename(COLUMN_NAME) + ' = sum(' + quotename(COLUMN_NAME) + ')'
                      from   INFORMATION_SCHEMA.COLUMNS
                      where  TABLE_NAME = @table
                      and    DATA_TYPE  = 'money'
                      for xml path('')
                  ), 
                  1, 1, ''
               ) + char(13)
            + 'from ' + max(quotename(@table)) + char(13)
            + ')' + char(13)
            + 'select a.table_name, a.column_name, a.total_sum ' + char(13)
            + 'from   cte ' + char(13)
            + 'cross apply (' + char(13)
            + char(9) + 'values' + char(13)
            + stuff
            (
              (
                  select    ',' + '(''' + TABLE_NAME + ''', ''' + COLUMN_NAME + ''',' + quotename(COLUMN_NAME) + ')'
                  from   INFORMATION_SCHEMA.COLUMNS
                  where  TABLE_NAME = @table
                  and    DATA_TYPE  = 'money'
                  for xml path('')
              ),
            1, 1, ''
            )
            + ') a (table_name, column_name, total_sum)' + char(13)