Query to fetch the Yesterday's Data

Seems to be easy question. And many of you may be already knew 2-3 ways of doing it. Here is the query I use normally to get the all the data from the previous day(Yesterday).

SELECT Id, OrderId, CustomerId FROM Orders WHERE Date >= DateAdd(DD, DateDiff(DD, 0, GETDATE())-1, 0) AND Date < DateAdd(DD, DateDiff(DD, 0, GETDATE()), 0)

Make it more readable and scalable using variable

DECLARE @YesterDay DATETIME, @Today DATETIME SET @YesterDay = DateAdd(DD, DateDiff(DD, 0, GETDATE())-1, 0) SET @Today = DateAdd(DD, DateDiff(DD, 0, GETDATE()), 0) SELECT Id, OrderId, CustomerId FROM Orders WHERE  Date >= @YesterDay AND Date < @Today

Logic : Basically above WHERE conditions is like - Greater than Equal to Yesterday and Less than Today.

This DateAdd(DD, DateDiff(DD, 0, GETDATE())-1, 0) gives Yesterday's date with time as 00:00:00.

And this DateAdd(DD, DateDiff(DD, 0, GETDATE()), 0)  gives today's date with time as 00:00:00.

You can do a quick check by executing -

SELECT DateAdd(DD, DateDiff(DD, 0, GETDATE())-1, 0) AS YDay ,DateAdd(DD, DateDiff(DD, 0, GETDATE()), 0) as ToDay

Reason for doing this way instead of using some obvious ones – As you may heard this from many SQL experts, “Whenever possible never use CONVERT/CAST or any functions in WHERE clause on table's column.”

Question is Why?

Well whenever you use the any function on a column , SQL Server no longer uses the Index define on particular column. And use of a CAST or CONVERT functions slows down the query execution considerably.

You may say, I used the DateAdd and DateDiff function in the WHERE clause. Yes, I used them, but NOT on Date column from the table. I used them with the Getdate function which is more of a constant and NOT part of the table's column.

Query Optimization Tip :

Whenever possible never use CONVERT/CAST or any functions in WHERE clause on table's column.

In future I'll have some more posts on Date comparison in WHERE condition. Also some more simple tricks to optimized the everyday's queries.

 

Mangal Pardeshi
SQL MVP

UNPIVOT Multiple Columns

Unlike PIVOT which de-normalizes the data, UNPIVOT is more helpful in getting your data back to a more normalized form.

UNPIVOT performs the opposite operation to PIVOT by rotating columns of a table-valued expression into column values.

For a single column UNPIVOT examples and for more on PIVOT and UNPIVOT you can read from Microsoft Books Online - Using PIVOT and UNPIVOT

In this article I’ll try to show you how to UNPIVOT multiple columns in a single query. There is simple trick to do that, if you are familiar with the UNPIVOT operator you will find it easy to understand.

First lets create some sample data :

-- Create sample table CREATE TABLE Suppliers (Id INT, Product VARCHAR(500), Supplier1 VARCHAR(500), Supplier2 VARCHAR(500), Supplier3 VARCHAR(500), City1 VARCHAR(500), City2 VARCHAR(500), City3 VARCHAR(500) ) GO -- Load Sample data INSERT INTO Suppliers SELECT 1, 'Car', 'Tata Motors', 'Bajaj', 'Mahindra', 'Jamshedpur','Pune','Mumbai' UNION ALL SELECT 2, 'Bike', 'Bajaj', 'Hero Honda', 'Suzuki', 'Pune', 'New Delhi', 'Chandigarh' UNION ALL SELECT 3, 'Cycle', 'Hercules', 'Hero', 'Atlas', 'Mumbai', 'Banglaore', 'Pune' GO -- Test sample data SELECT Id, Product, Supplier1, Supplier2, Supplier3, City1, City2, City3 FROM Suppliers GO

Here is how our sample table looks like :

Id	Product	Supplier1	Supplier2	Supplier3	City1	City2	City3
1	Car	TataMotors	Bajaj	Mahindra	Jamshedpur	Pune	Mumbai
2	Bike	Bajaj	Hero Honda	Suzuki	Pune	New Delhi	Chandigarh
3	Cycle	Hercules	Hero	Atlas	Mumbai	Bangalore	Pune

And as you can see here we have 2 columns which needs to be UNPIVOT, first is Supplier and second is there respective Cities.  If it was single column to be UNPIVOTed it could have been a straight forward task.  Thing is you can write a query with 2 UNPIVOT operators, but question is how to JOIN two UNPIVOT sub queries correctly so we will get the each supplier with its respective city next to it in second column?

As I said earlier there is simple trick to do that.  See the following query and its WHERE condition :

SELECT Id,     Product,     ROW_NUMBER()OVER(Partition By Id Order By Suppliers) as SuppId,     SupplierName,     CityName FROM ( SELECT Id, Product, Supplier1, Supplier2, Supplier3, City1, City2, City3 FROM Suppliers ) Main UNPIVOT ( SupplierName FOR Suppliers IN (Supplier1, Supplier2, Supplier3) ) Sup UNPIVOT ( CityName For Cities IN (City1, City2, City3) ) Ct WHERE RIGHT(Suppliers,1) =  RIGHT(Cities,1)

And here is the Output of the query :

Id	Product	SuppId	SupplierName	CityName
1	Car	1	Tata Motors	Jamshedpur
1	Car	2	Bajaj	Pune
1	Car	3	Mahindra	Mumbai
2	Bike	1	Bajaj	Pune
2	Bike	2	Hero Honda	New Delhi
2	Bike	3	Suzuki	Chandigarh
3	Cycle	1	Hercules	Mumbai
3	Cycle	2	Hero	Bangalore
3	Cycle	3	Atlas	Pune

So the trick was this where condition -

WHERE RIGHT(Suppliers,1) =  RIGHT(Cities,1)

There are other ways also to UNPIVOT the multiple columns, may be some other time I’ll post them too. 

Source of inspiration for this post is following thread on MSDN forums - http://social.msdn.microsoft.com/Forums/en-US/transactsql/thread/54626179-ee9f-4db7-a31e-c02104bdd6beAt 

At the end of it, OP also come up with his own solution he got from SQLTeam’s forums.

Mangal Pardeshi

RunningValue Function (Reporting Services) – Calculating Running Totals

In one of my previous posts I talked about Calculating Running Totals in T-SQL.  Now I will show you how you can calculate the running totals in Sql Server Reporting Services(SSRS).  Yes, it is very much possible with RunningValue function in SSRS and also very easy compare to doing it in SQL.  

The syntax for RunningValue function goes like this -

RunningValue(expression, function, scope)

• expression : The expression on which to perform the aggregation, for example, [Quantity].
• function : The name of the aggregate function to apply to the expression, for example- Sum.
• scope :The name of a dataset, data region, group or Nothing.

See the table below and RunningTotal column which is Cumulative SUM of Quantity column. 

ShipId	OrderId	ShipDate	Quantity	RunningTotal
1	1	2009-02-01 12:06:16.820	10	10
2	1	2009-02-02 16:16:16.820	15	25
3	2	2009-02-01 13:26:16.820	20	45
4	2	2009-02-03 17:40:16.820	12	57
5	2	2009-02-04 13:05:16.820	15	72
6	3	2009-02-03 14:25:16.820	25	97
7	3	2009-02-04 15:50:16.820	50	147
8	3	2009-02-05 19:40:16.820	30	177
9	4	2009-02-06 15:30:16.820	20	197
10	4	2009-02-07 16:20:16.820	10	207
11	5	2009-02-05 17:05:16.820	35	242

For achieving that in SSRS, add extra column in your Report’s Layout Page and put following expression in it-

=RunningValue(Fields!Quantity.Value, Sum, Nothing)

Yes, it is easy and simple, isn’t it?  But what about when you want the RunningTotals for group of records?  Like for above example you want the Running Totals for each orderId separately.  See the table below :

ShipId	OrderId	ShipDate	Quantity	RunningTotal
1	1	2009-02-01 12:06:16.820	10	10
2	1	2009-02-02 16:16:16.820	15	25
3	2	2009-02-01 13:26:16.820	20	20
4	2	2009-02-03 17:40:16.820	12	32
5	2	2009-02-04 13:05:16.820	15	47
6	3	2009-02-03 14:25:16.820	25	25
7	3	2009-02-04 15:50:16.820	50	75
8	3	2009-02-05 19:40:16.820	30	105
9	4	2009-02-06 15:30:16.820	20	20
10	4	2009-02-07 16:20:16.820	10	30
11	5	2009-02-05 17:05:16.820	35	35

Now for achieving that you need do followings :

• First go to Report Layout page and add a new Group.   Give some name to the group.  If you don’t gave any name the default name would be something like “table1_Group1”.  Just note that.  And add OrderId to “Group On” expression.
• Now change the expression at RunningTotal column as

  =RunningValue(Fields!Quantity.Value,SUM,"table1_Group1")

        Now if you have noticed I have replaced the scope Nothing to Group name “table1_Group1” .

Well after adding the extra group in the report you might see blank spaces after every  OrderId change. If you don’t want those blanks and want continuous report, then go to the property page of the new group added and set Visible to “false”.

Mangal Pardeshi

SQL MVP

Script All the Stored Procedures in The Database

In Sql Server 2005 and 2008 you can script the stored procedure in Management Studio by right clicking on Store Procedure name and clicking on “Script Store Procedure as” and then “Create To”.

But if you want to script all the Stored Procedures in the database programmatically, then here is the simple T-SQL query for it -

To script All the Stored Procedures in the Database :

SELECT    O.Name as ProcName         ,M.Definition as CreateScript         ,O.Create_Date         ,O.Modify_Date FROM sys.sql_modules as M INNER JOIN sys.objects as O ON M.object_id = O.object_id WHERE O.type = 'P'

If the Stored Procedure is created with ENCRYPTION option then you will get the NULL in the definition column.

Similarly,

To script All the Views in the Database :

SELECT    O.Name as ProcName         ,M.Definition as CreateScript         ,O.Create_Date         ,O.Modify_Date FROM sys.sql_modules as M INNER JOIN sys.objects as O ON M.object_id = O.object_id WHERE O.type = 'V'

To script All the Functions in the Database :

SELECT    O.Name as ProcName         ,M.Definition as CreateScript         ,O.Create_Date         ,O.Modify_Date FROM sys.sql_modules as M INNER JOIN sys.objects as O ON M.object_id = O.object_id WHERE O.type = 'FN'

For scripting all Triggers small modification is required, instead of sys.objects I joined the sys.triggers with sys.sql_modules.

To script All the Triggers in the Database :

SELECT    O.Name as ProcName         ,M.Definition as CreateScript         ,O.Create_Date         ,O.Modify_Date FROM sys.sql_modules as M INNER JOIN sys.triggers as O ON M.object_id = O.object_id

Mangal Pardeshi
SQL MVP

How To Split A Comma Delimited String

In one of my previous posts I wrote about “How to Create a Comma Delimited List”.  Now I’ll show you an example with reverse action, that is Splitting a Comma Delimited String or array() of values.

There can be different types of Delimiters also : like Comma ' , ', vertical bar ' | ', Single space or a Tab.

For example here is our Sample Table -

Id	AllNames
1	A,B,C
2	A,B
3	X,Y,Z

And here is the expected output -

Id	Names
1	A
1	B
1	C
2	A
2	B
3	X
3	Y
3	Z

Create Sample Data :

-- Create Table for  Sample Data CREATE TABLE Test ( ID INT, AllNames VARCHAR(100) ) GO -- Load Sample Data INSERT INTO test SELECT 1, 'A,B,C' UNION ALL SELECT 2, 'A,B'  UNION ALL SELECT 3, 'X,Y,Z' GO -- Verify the Sample Data SELECT Id, AllNames FROM Test

And here is the query for How to split a comma delimited string :

;WITH Cte AS (     SELECT         id,         CAST('<M>' + REPLACE( Allnames,  ',' , '</M><M>') + '</M>' AS XML) AS Names     FROM Test ) SELECT     ID,     Split.a.value('.', 'VARCHAR(100)') AS Names FROM Cte CROSS APPLY Names.nodes('/M') Split(a)

Acknowledgement : Well seriously don’t know.  Somewhere I came across this solution while answering / participating  on MSDN Sql Server Forums.  So credit goes to my fellow Moderators/answrers on MSDN Forums.

Actually whatever expertise I gained on T-SQL and Sql Server is by participating / answering to the posts on online forums.  I’m one of those freaks who hate to read books ;)

- Mangal Pardeshi