Case in Select statement in SQL Server

DROP TABLE VENKAT_TABLE GO CREATE TABLE VENKAT_TABLE(ID INT, NAME VARCHAR(100),MARKS INT) INSERT INTO VENKAT_TABLE VALUES (1,'VENKAT',20) INSERT INTO VENKAT_TABLE VALUES (2,'SUBA',80) INSERT INTO VENKAT_TABLE VALUES (3,'LAKSHMI',45) INSERT INTO VENKAT_TABLE VALUES (4,'SANTHI',70) SELECT ID, NAME, CASE WHEN MARKS >50 THEN 'GOOD' ELSE 'BAD' END AS RESULT FROM VENKAT_TABLE

Order of Execution of Select Statement

This article is not clearly displayed in this blog, I have posted the same article in my other blog too. http://www.c-sharpcorner.com/Blogs/4536/order-of-execution-of-select-statement.aspx One of my blog reader have asked a query on SQL Server query execution order. Thought of writing an article on the same. select * from Student where id< 5000 group by studentID having subjectid=10 order by student name Here is the order of execution for your select statement. FROM --> Which Primary table ON --> On which column to join JOIN -->With which table, you want to join WHERE --> what are the conditions to filter the record GROUP BY --> on what basis, you want to group. WITH CUBE or WITH ROLLUP --> Show the data in the form of knowledge cubes. HAVING --> Another filter criteria S ELECT --> Get the data DISTINCT --> Remove duplicates ORDER BY --> Display in this order TOP --> Display only this much. That's really awesome processing of your query. My only concern is, why we are grouping the data afterwards we are having another filter criteria like having. May be having can be placed front before grouping it. Anyway, I will put this question to Microsoft. For our example, select * from Student where id < 5000 group by studentID having subjectid=10 order by student name The order of execution is, from -->where --> group by -->having --> select -->; Order by Cheers, Venkatesan prabu .J http://venkattechnicalblog.blogspot.com/ http://www.kaashivinfotech.com/

Horizontal ruler in HTML

I happened to use HTML for my company website (http://www.kaashivinfotech.com/). During my design for segregating the content, I've used table row and table data with lines in the boundary like, OOps, it's a costliest work to do and it's not efficient way to give a break line between the contents.

On my random search, I found the horizontal ruler in my VS tool box. Awesome, Here is the one line code to achieve the same,

---

To provide colour to the ruler

---

To provide the size to the ruler. Here is an option

---

width - Indicates the length of the ruler

size - Indicates the thickness of the ruler.

Cheers,

Venkatesan Prabu .J

Combining two views in SQL Server

Let's talk about views in SQL Server. Views are nothing but virtual tables which covers the table in SQL Server.

Am creating two tables,

DROP TABLE VENKAT_TABLE
GO
CREATE TABLE VENKAT_TABLE(ID INT, NAME VARCHAR(100))
GO
INSERT INTO VENKAT_TABLE VALUES(1,'SUBA')
GO
INSERT INTO VENKAT_TABLE VALUES(1,'ARUN')
GO
DROP TABLE VENKAT_SECOND_TABLE
GO
CREATE TABLE VENKAT_SECOND_TABLE(ID INT, AGE INT)
GO
INSERT INTO VENKAT_SECOND_TABLE VALUES(1,20)
GO
INSERT INTO VENKAT_SECOND_TABLE VALUES(1,30)
GO

-- Now am creating the views for the tables.

-- Views are nothing but virtual table which is like a mask on the table. For security reasons, instead of allowing the user to access the tables directly we will use views.

CREATE VIEW VENKAT_VIEW
AS
SELECT * FROM VENKAT_TABLE
GO
CREATE VIEW VENKAT1_VIEW
AS
SELECT * FROM VENKAT_TABLE
GO
CREATE VIEW VENKAT_SECOND_VIEW
AS
SELECT * FROM VENKAT_SECOND_TABLE
GO

Joining two views

------------------------------------------------------------------------------------
SELECT V1. * FROM VENKAT_VIEW V1 INNER JOIN VENKAT_SECOND_VIEW V2
ON V1.ID=V2.ID

Merging the results sets of the view.

(For merging the result set, we can use union all or union operator)

------------------------------------------------------------------------------------
SELECT * FROM VENKAT1_VIEW UNION ALL
SELECT * FROM VENKAT_VIEW

Cheers,
Venkatesan Prabu .J
Head - http://www.kaashivinfotech.com/
http://venkattechnicalblog.blogspot.com/

Enable Backup compression in SQL Server

Backup compression is a very important feature introduced in SQL Server 2008. Using this technique, the daily backups from the server were compressed and lot of spaces were saved.

"Usually in production servers, DBA's /jobs will take the backup frequently. In least case, 1 backup per day. The file will be ended with *.bak". The size of the backup depends on the size of the database. To avoid more space for the backup's, Microsoft have introduced this backup compression technique." We will see more details on the new compression techniques in my future article.


Let's see how to enable the backup compression option in SQL Server.


USE master
GO
EXEC sp_configure 'backup compression default'
GO
EXEC sp_configure 'backup compression default', '1'
RECONFIGURE WITH OVERRIDE
GO
EXEC sp_configure 'backup compression default'
GO

Cheers,Venkatesan Prabu .J

Head - www.KaaShivinfotech.com

http://venkattechnicalblog.blogspot.com/

Get the description of the Collation settings

In my previous post, we have seen how to identify the collation settings in the server. The output which we got is not much clear to the normal users. That's why, Microsoft have introduced a built in function to identify the collation which can be understood by normal users.

The function name is sys.fn_helpcollations()

In my previous post, I got my collation setting for my server as, 'Latin1_General_CI_AI'. Below is the query to get the detailed description of the collation.

SELECT description FROM sys.fn_helpcollations() WHERE name = 'Latin1_General_CI_AI'

The output is,

Latin1-General, case-insensitive, accent-insensitive, kanatype-insensitive, width-insensitive

Kanatype - It's Japanese support data
Width - Width of the data is not considered.

Try your query like below to get the collation settings and their detailed description.

SELECT description FROM sys.fn_helpcollations() WHERE name = 'Latin1_General_CI_AI'

Cheers,
Venkatesan Prabu .J
Head - www.KaaShivinfotech.com
http://venkattechnicalblog.blogspot.com/

Identify the Collation settings of the server

Here is the handy query to identify the Collation settings on the Server.

SELECT SERVERPROPERTY('Collation')

The output is,

Latin1_General_CI_AI
It indicates my server will support Latin general language, with Case insensitivenss and Accent insensitiveness.

Cheers,
Venkatesan Prabu .J
Head - www.KaaShivinfotech.com
http://venkattechnicalblog.blogspot.com/

How to find Network Adapters available in your machine??

Option 1:
In Control panel, you can see the available network adapters.


Option 2:
Goto Control Panel -> Device Manager -> Network Adapter

Cheers,

Venkatesan Prabu .J

Managing Director - www.Kaashivinfotech.com

http://venkattechnicalblog.blogspot.com/

Accessing Text Box content

I have seen the below query in a popular forum. Thought of writing something on this. This is the below query,

Conversion failed when converting the varchar value 'System.Web.UI.WebControls.TextBox' to data type int.

I cant understand why it will occur,i insert the data regarding to the correct datatype only

The guy is trying to access the text box value and he want to convert the value to integer.

Guessing, he is trying to get the value 'System.Web.UI.WebControls.TextBox'. Error indicates, the guy is trying to access the textbox property instead of text box data. In turn you need to access the textbox content like textbox.text and after wards convert the same to integer.

Cheers,
Venkatesan Prabu .J
Head - www.KaaShivinfotech.com
http://venkattechnicalblog.blogspot.com/

Naming the Constraint in sql server

Dynamically naming the constraint:

Constraint is nothing but a condition placed on the column or object. Let's see a small example to create a Primary Key constraint.

CREATE TABLE SANTHOSH_TABLE (NAME VARCHAR(100),ID INT PRIMARY KEY,DOB DATETIME)

---- INSERT RECORDS INTO THE TABLE ----------
INSERT INTO SANTHOSH_TABLE VALUES('VENKAT',1,'1/1/2010')
INSERT INTO SANTHOSH_TABLE VALUES('LINGAM',2,'1/1/2009')
INSERT INTO SANTHOSH_TABLE VALUES('ILAM',3,'1/2/2010')
INSERT INTO SANTHOSH_TABLE VALUES('SANTHOSH',4,'1/3/2010')
INSERT INTO SANTHOSH_TABLE VALUES('SIVARAM',5,'1/4/2010')

SELECT * FROM SANTHOSH_TABLE

The Primary key constraint name is
PK__SANTHOSH__3214EC2762AFA012 which looks tougher to remember the name. This name is automatically generated by SQL Server. Can we have a specific name to the Constriant?

Below query will drop the constraint located in to your table.

--------- DROP CONSTRAINT ON THE TABLE
ALTER TABLE SANTHOSH_TABLE DROP CONSTRAINT PK__SANTHOSH__3214EC2762AFA012

Now, lets see how to name a constraint.

---- DROPPING THE TABLE------------
DROP TABLE SANTHOSH_TABLE

---- NAMING THE CONSTRAINTS EXPLICITLY------------
CREATE TABLE SANTHOSH_TABLE (NAME VARCHAR(100),ID INT ,DOB DATETIME,
CONSTRAINT PK_ID_SANTHOSH PRIMARY KEY (ID))

Now, you constraint name is PK_ID_SANTHOSH.

Happy Learning!!!

Cheers,

Venkatesan Prabu .J

Performance tuning Query

This is Dastagiri from hyderabad .I have two years experience in Database’s SQL Server 2005, MySql, ADS servers.But I dint not understand how to apply performance tuning for large time taking queries.Could you please send me any material or video links to me.


Thanks,
Dastagiri.

Sir,

Advising you to get some good books on performance tuning.

http://www.sql-server-performance.com/tips/performance_main.aspx

http://www.mssqltips.com/category.asp?catid=9

http://msdn.microsoft.com/en-us/library/ff647793.aspx

Here are some of the useful links to start your performance tuning with SQL Server

Cheers,
Venkatesan Prabu .J
www.Kaashivinfotech.com

Query on DateTime operations

Anyway, here is the tips to resolve the problem.

Not working:

select * from Production_Table WHERE [Rep_Code] IN ('117','118','146','147','148','701','702','704','705','706','707','709','710','711','712','713','202') and Rep_Type LIKE '6%' and CONVERT(VARCHAR(8),CONVERT(DATETIME,(Load_Date)),112) between '20110120' and '20110126'

Error message:
Server: Msg 242, Level 16, State 3, Line 1 The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value.

Working:

SELECT CONVERT(VARCHAR(8),CONVERT(DATETIME,(Load_Date)),112) FROM from Production_Table WHERE [Rep_Code] IN ('117','118','146','147','148','701','702','704','705','706','707','709','710','711','712','713','202') and Rep_Type LIKE '6%'


So, the loop hole is with the between operator.

Step 1: Most probably, the issue is with the data. It’s a data issue.
Step 2: Check your objects whether any changes happened on the column.
Step 3: Check for the data, any manual entry to add special symbols (Single quotes) may happen.
Step 4: Use a loop operations to identify the exact error data or use top operator to identify it manually.

All the best and sorry for my delay response.

Cheers,
Venkatesan Prabu .J
Managing Director – KaaShiv Info Tech

MVP / MVM / MCITP / MCTS / MCAD / CCNA / QAI
Microsoft SQL Server MVP / Mind Cracker MVP

Website : http://www.kaashivinfotech.com/
Blog : http://venkattechnicalblog.blogspot.com/
Profile : http://beyondrelational.com/members/jvprabhusanthi/default.aspx

Check my Microsoft Profile for more details about me : https://mvp.support.microsoft.com/default.aspx/profile/venkatesan
-------------------------------------------------------------------------------------------
Hi Venkat,

Did you get a chance to look at this email?

Regards
Alex Madaswamy
On Fri, Jan 28, 2011 at 2:31 PM, > wrote:
Hi Venkat,

I was looking through some forums to find a solution my issue and got your blog information and your email id. Can you please help me to resolve this issue?

We have a table with more than 1M records and we are retrieving records from this table in my application. This was working fine till two days back, but now its throuwing an error. See below the query and the error message we are getting.

select * from Production_Table WHERE [Rep_Code] IN ('117','118','146','147','148','701','702','704','705','706','707','709','710','711','712','713','202') and Rep_Type LIKE '6%' and CONVERT(VARCHAR(8),CONVERT(DATETIME,(Load_Date)),112) between '20110120' and '20110126'

Please note:
All the fields in WHERE condition are of the data type VARCHAR
Values in the field Load_Date is in the format yymmdd

Error message:
Server: Msg 242, Level 16, State 3, Line 1The conversion of a char data type to a datetime data type resulted in an out-of-range datetime value.

I tried this as well:

Removed the condition for the Load_Date from the WHERE condition and ran the query with just Rep_Code and Rep_Type, query returns the value without any issue.
Removed the condition for the Load_Date from the WHERE condition and included in the SELECT part and ran the query with just Rep_Code and Rep_Type, query runs well without any issue. Below is the modified query.
SELECT CONVERT(VARCHAR(8),CONVERT(DATETIME,(Load_Date)),112) FROM from Production_Table WHERE [Rep_Code] IN ('117','118','146','147','148','701','702','704','705','706','707','709','710','711','712','713','202') and Rep_Type LIKE '6%'
Can you please help me to find a solution for this issue?

Thanks in advance,
Alex Madaswamy