Rowcount for all tables by year in dbo schema - sql

Question

I'm looking for a query in SQL Server that will return the total number of rows for a given year across all tables in a particular schema, in this case dbo.
All tables in this schema have a column named UPDT_TS which stores the last time the row was updated and can be used for this date calculation.

Answer 1

You can use a simple cursor, and dynamic SQL.
declare #v_Year int
set #v_Year = 2013
declare #v_TableName nvarchar(256)
declare #v_SQL nvarchar(max)
declare #v_Count int
declare #v_ResultTable table
(
TableName nvarchar(256),
[RowCount] int
)
declare cur cursor local fast_forward read_only for
select t.name from sys.tables as t
inner join sys.columns as c on t.object_id = c.object_id
where c.name = 'UPDT_TS' and t.schema_id = schema_id('dbo')
open cur
while (1=1)
begin
fetch next from cur into #v_TableName
if ##FETCH_STATUS <> 0
break;
set #v_SQL = 'select #v_Count = count(*) from '+QUOTENAME(#v_TableName)+' where year(UPDT_TS) = ' + cast(#v_Year as nvarchar(4))
exec sp_executesql #v_SQL, N'#v_Count int output', #v_Count output
insert into #v_ResultTable
select #v_TableName, #v_Count
end
close cur
deallocate cur
select * from #v_ResultTable
EDIT
Just saw Goat's answer after posting :) looks like we hade the same idea :)

Answer 2

Assuming you have a Results table to insert records into, you can do this with a simple cursor:
DECLARE #Iterator varchar(255)
,#strSQL varchar(MAX)
DECLARE xyz CURSOR CURSOR FAST_FORWARD READ_ONLY
FOR
SELECT t.name
FROM sys.schemas s
JOIN sys.tables t
ON s.schema_id = t.schema_id
WHERE s.name = 'dbo'
OPEN xyz
FETCH NEXT FROM xyz
INTO #Iterator
WHILE ##FETCH_STATUS = 0
BEGIN
SET #strSQL = 'INSERT INTO Results
SELECT COUNT(*) as Rows, '''+#Iterator+''' as TableName
FROM '+QUOTENAME(#Iterator)+'
WHERE YEAR(UPDT_TS) = 2013
'
EXEC (#strSQL)
FETCH NEXT FROM xyz
INTO #Iterator
END
CLOSE xyz
DEALLOCATE xyz
GO
Whenever dealing with dynamic sql it can be helpful to change EXEC (#strSQL) to PRINT (#strSQL) to ensure you've got the syntax nailed down.

Answer 3

This will work also:
DECLARE #sql NVARCHAR(max)
,#year INT
SET #year = 2013
SELECT #sql = 'select sum (total) from (' + SUBSTRING(cast((
SELECT ' union select count(*) as Total
from ' + quotename(table_name) + '
where
UPDT_TS between dateadd(year,#year-1900,0) and dateadd(s,-1,dateadd(year,#year-1900+1,0))'
FROM information_schema.columns
WHERE column_name = 'UPDT_TS'
AND TABLE_SCHEMA = 'dbo'
FOR XML path('')
) AS NVARCHAR(max)), 8, 8000) + ') as Presum'
PRINT #sql
EXEC sp_executesql #sql
,N'#year int'
,#year = #year