Total row counts for all table in YOUR_DATABASE:

SELECT      SCHEMA_NAME(A.schema_id) + '.' +
        A.Name, SUM(B.rows) AS 'RowCount'
FROM        sys.objects A
INNER JOIN sys.partitions B ON A.object_id = B.object_id
WHERE       A.type = 'U'
GROUP BY    A.schema_id, A.Name
GO

Select an OrderID always before the current passing OrderID:

select an OrderID before the OrderID you are passing. check the below scenario for more clarification.

 ;WITH CTE AS 

(

  SELECT

    rownum = ROW_NUMBER() OVER (ORDER BY orderID),orderID FROM Orders

) 

SELECT 

  cur.orderID as CurrentID , prev.orderID as PrevID

 FROM CTE cur

INNER JOIN CTE prev on prev.rownum = cur.rownum - 1

where cur.orderID=27 or cur.orderID=29

OUTPUT:

Difference between Function and Store Procedure:-

Check all tables name that contain with trigger :

Select 
[tgr].[name] as [trigger name], 
[tbl].[name] as [table name]
from sysobjects tgr 
join sysobjects tbl
on tgr.parent_obj = tbl.id
WHERE tgr.xtype = 'TR'
Check Below the output will come like :

First column is for trigger name and second column contains table name that having trigger.

Check database total size in use :-

SELECT DB_NAME(database_id) AS DatabaseName,
       Name AS Logical_Name,
       Physical_Name,
       (size * 8) / 1024 SizeMB
FROM sys.master_files
WHERE DB_NAME(database_id) = 'YOUR_DB'

Check two table where columns are not matching :-

select column_name from INFORMATION_SCHEMA.COLUMNS 
where TABLE_NAME='Table_name1'
except
select column_name from INFORMATION_SCHEMA.COLUMNS 
where TABLE_NAME='Table_name2'