Pagination Using Query DSL Native Qs

Pagination  using Query DSL

Recently i got my self into a situation while using  hibernate generated query for paginating  results from database. I was using Query DSL with Spring Data JPA  and Sql Server 2012 database. I implemented pagination using offset and limit methods provided by dsl and it all seemed to be working perfectly until i had a look at the generated queries. It was fine for first page but for the subsequent pages, generated query was using top keyword bringing all the records in to memory and then giving the set of required data filtering those records. These thing were being done by hibernate behind the scene off course but again the purpose of server side pagination  was lost. So we used Native Sql queries generated by dsl and i am documenting it here for myself and any one else looking for this solution.

We were using maven as build tool for this project so lets start with adding the required maven dependencies  and pluggin in the pom.xml

<dependency>
  <groupId>com.mysema.querydsl</groupId>
  <artifactId>querydsl-sql</artifactId>
  <version>${querydsl.version}</version>
</dependency>    
      
<dependency>
  <groupId>com.mysema.querydsl</groupId>
  <artifactId>querydsl-sql-codegen</artifactId>
  <version>${querydsl.version}</version>
  <scope>provided</scope>
</dependency>

<plugin>

  <groupId>com.mysema.querydsl</groupId>

  <artifactId>querydsl-maven-plugin</artifactId>

  <version>${project.version}</version>

  <executions>

    <execution>

      <goals>

        <goal>export</goal>

      </goals>

    </execution>           

  </executions>

  <configuration>

    <jdbcDriver>your datbase driver class name</jdbcDriver>

    <jdbcUrl>your datbase url</jdbcUrl>

    <packageName>com.mycompany.mydomain</packageName>

    <targetFolder>target/generated-sources/java</targetFolder>   

    <jdbcUser>.....</jdbcUser>
    <jdbcPassword>.... </jdbcPassword>
    <tableNamePattern>comma separated table names</tableNamePattern>   

  </configuration>

  <dependencies>

   <dependency>
    <groupId>net.sourceforge.jtds</groupId>
    <artifactId>jtds</artifactId>
    <version>1.2</version>
   </dependency>

  </dependencies>

</plugin>

** use query dsl version 3.1 or greater because Q classes generation restiction 

   to the tables provided by comma separated table names are not supported before 

   Query dsl 3.1

Run goal clean install to generate Q classes for your tables.Q Classes will be

generated in target folder mentioned in above configuration.

Now use this code to create SQl query object and use availabe Dsl api to write

pagination query for ex:

                SQLTemplates dialect = new SQLServer2012Templates();
                SQLQuery query = new SQLQueryImpl(Connection, dialect); 

build your query using this SQl query object and call offset and limit on it to

generate paginated query which u will execute using list method of dsl api. 

query should be something like

               Query.distinct().offSet(offSet).limit(pageSize);

               Query.list(expr);   

Logic for calculating offset:

Count mrthod of dsl will give total no of records for your query,dividing it by 

pageSize will give the total no of pages,remember to ceil the division result to

get correct no of total pages. Use these data to calculate the off set for each

request.

**** Combination of distinct offset and limit doesnot work for SQl SErver 2008 

     and below as offset is implemented using RowNumber ranking function which needs

     to have order by clause.Calling distinct on the resultant query doesnt generate

     correct SQl for sql server.Yo will not get distinct records :(

Hope dis helps :)

How to fix your Windows Vista / Windows XP after it shows a blank screen after login.

A few days ago, I was referred by a friend of a friend, who had another friend who was having some problems with her PCs (pretty far huh?). She said that she can’t use her PCs anymore as both show a blank screen after Windows boot-up. It was weird that both PCs were showing the same problem that I had to see it myself. It got even weirder as one PC had Windows Vista, and the other had Windows XP.
The problem: Windows Vista or Windows XP displays a blank screen showing only the mouse pointer after booting-up (after the login screen which is usually after clicking the username).

Solution for Windows Vista / Windows XP Blank Screen after Login
Make sure first that the Task Manager is working by pressing CTRL+ALT+DEL, and choosing Task Manager. If Task Manager doesn’t work, then this guide cannot help you.
Moreover, unless specified, the steps below are both applicable for Windows Vista and Windows XP.

1. Launch the Task Manger and Restore your Desktop
Press CTRL+ALT+DEL and then go to File->New Task


When the Run window appears, type Explorer or Explorer.exe or C:\Windows\Explorer


Important: If this does not restore your desktop, your desktop icons and windows taskbar, then you should stop reading this now as this guide would not be able to help you.

2. Check your Registry
Create a New Task again by using the Task Manager. Since you now have the Taskbar restored, you can do this also by clicking Windows Start and choosing Run. When the Create a New Task or Run window appears, type regedit.


Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon. Once you’ve clicked on WinLogon look for Shell in the right pane. Double-click on Shell and the value for Shell should only be Explorer.exe.


As can be seen above, there is an additional entry which is C:\Windows\System32\keyboard\services.exe which the Shell key refers to. Normally what we should do is just delete this additional entry and leave Explorer.exe in the field. However, if you’re seeing that value above, your computer is now infected with a Malware – specifically a Keylogger.
Important: If the value above is not just Explorer.exe but has a different additional entry (and not C:\Windows\System32\keyboard\services.exe) den just make it to explorer.exe only delete nything which follows it .
But as soon as u restart ur pc it will come again bcoz the malware is still dere go to step 3 to remove malware first then again change the registry to explorer.exe as told in step 5


3. Download and Install Unlocker software (i  will advise u to first scan ur my computer with any gud antivirus prog in safe mode bcoz nowaday they catch dis malware and remove it in but only in safe mode i m using a avg premium licenced version and it caught 24 instances of win32 sality virus for me if it works for u jump to step 5 no need of step 3 and 4  if not u can go down with the proceedings)
We won’t be using any Malware scanner or virus scanner as I have not found any which can remove this Malware. Moreover, if there is a scanner out there which could remove this Malware, I think using Unlocker is still the most simple way where you have total control of what is going on.
As I’ve mentioned, download Unlocker from CNET as their official website is currently down. Once you’ve successfully downloaded the software, install it.

4. Delete the Malware files
Go to C:\Windows\System32\keyboard\ through Windows Explorer or by typing this in the Create New Task or Run command.


You should be able to see the services.exe file. DON’T execute or double click it. Right click on it and if you’ve successfully installed Unlocker, you should be able to select it like below:


The Unlocker program should now launch and show you the Processes that are using services.exe. Select all the processes and choose, Kill Process.


Once there is no more process using services.exe, quit Unlocker, and then delete services.exe. Make sure to delete it at the Recycle Bin as well. If we don’t use Unlocker, we won’t easily delete the Malware.

For Windows Vista
Go to the following folders and delete the files indicated. Use Unlocker as needed.
C:\ProgramData\Application Data\Fearghus\ – delete lsass.exe
C:\ProgramData\Fearghus\ – delete lsass.exe
C:\ProgramData\Application Data\microsoft\usb2.0\ – delete usb-hi.exe
C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Startup\ – delete kbdrv16.com
Important: Use the Create New Task or Run window as sometimes using Windows Explorer doesn’t work saying that the folder does not exist.

For Windows XP
Go to the following folders and delete the files indicated. Use Unlocker as needed.
C:\Documents and Settings\All Users\Application Data\Fearghus\ – delete lsass.exe
C:\Documents and Settings\All Users\Application Data\Microsoft\USB2.0\ – delete usb-hi.exe
C:\Documents and Settings\All Users\Start Menu\Programs\Startup\ – delete kbdrv16.com

5. Clean your Registry
Launch Registration editor again by making a new task through Task Manager or by using the Run command and entering regedit.


Go to HKEY_LOCAL_MACHINE \SOFTWARE\Microsoft\Windows\CurrentVersion\Run\ and then on the right pane click USB2.0 and Keyboard and then delete both.


Go to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon and then double-click on Shell on the right pane to modify it (You can now modify it). Only Explorer.exe should be the value left.


Click Ok to accept the changes.
The only thing left to do now is restart Windows and test if the Windows desktop would still be blank.
That’s it! I hope I’ve helped you solve your problem on Windows Vista / Windows XP blank screen after login.

What's bothering Bihar's entrepreneurs?

What's bothering Bihar's entrepreneurs? Ask 'MBA Sabziwalla'

Patna: He is called the "MBA sabziwalla" and wants to make Bihar India's vegetable hub. Kaushlendra, an alumnus of the Indian Institute of Management-Ahmedabad (IIM-A), is now working towards pre-paid cards for buying vegetables but complains of irritating hurdles that discourage budding entrepreneurs.

Kaushlendra, who refused to join a multinational company like his peers as he wanted to work towards making Bihar a better place, says something as simple as encashing a cheque can take days.
"There are many small things that impede the growth of an entrepreneur in Bihar. We cannot compete with entrepreneurs of other states because other support services come at huge indirect and direct costs," Kaushlendra, a topper of the IIM-A's 2007 batch, told IANS in an interview.
His earlier project of selling vegetables through ice-cooled push-carts became a hit in Bihar and Kaushlendra, in his 20s, now is working hard on his Organised Vegetable Marketing (ORVEM) project to enable people to buy vegetables through pre-paid cards.
But he is unhappy as a cheque deposited three months back has still not been credited.
"A cheque of Rs.20,000 was deposited in my company account three months back and it has not been credited till date. When we inquired Jan 27 and sent a person to the State Bank of India branch in Hilsa in Nalanda district, we were astonished to find they have debited it to another's account Dec 15, 2010. And till date they have not sent the amount to my bank in Patna," he rued.

"They say they'll courier the cheque now, but I'm not sure they will...these small things have ruined many entrepreneurs in Bihar in the past and we do not know whether we will survive this or not," a frustrated Kaushlendra said.
He gave another example of the Madhya Bihar Gramin Bank's (MBGB) Kankarbagh branch in Patna not disbursing a loan amount.
"It sanctioned a loan for nine AC carts to our nine vendors under the government scheme but they are not disbursing the amount...what I have been able to understand is that the bank is looking for some under-the-table dealing that we never do or promote," the bespectacled youth said.
"The bank always procrastinates on this issue. The manufacturer of the cart is sitting on my head and we are finding ourselves helpless," Kaushlendra added.
He wondered how common people in the state manage to get their work done if an educated man like him faced so many problems.
A native of a village in Nalanda, which also happens to be Chief Minister Nitish Kumar's home district, Kaushlendra said he wanted to make vegetables the new brand of Bihar.
Hailing from a farmer family himself, he started his NGO Kaushalya Foundation two years ago and his push-cart was his first venture two years ago.
After topping IIM-A, he did extensive field work -- meeting farmers and studying cultivation techniques -- before he started the project.

Kaushlendra recalled that after doing his MBA, he and his friends and teachers from IIM-A developed a push-cart to make it easy for vendors to carry a vegetable load of up to 200 kg.
In a bid to establish direct links with vegetable growers, Kaushlendra has tied up with over 250 vegetable growers in different villages in Nalanda and Patna districts.
He has also tied up with the Agriculture Training and Management Agency (ATMA) to take his dream to vegetable producers in different parts of state.
Kaushlendra said Bihar has an enormous untapped potential for vegetables. The vegetables produced in fertile land near the Ganga river can mark a turnaround for the state if marketed properly.
He recently launched his push-cart service in Lucknow in Uttar Pradesh too and claims pre-paid cards to buy vegetables will help customers avoid the usual rush in busy markets and will also offer additional services.
The customers will be able to buy vegetables with the card even if they don't have cash and also get them at slightly cheaper rates.
Source: IANS

contact no TCS HRs

TCS Toll Free No: 1800-22-01-00
Email at ilp.support@tcs.com

:---- Contact Details of TCS HR ----:
Delhi: 66506555
Pune: 6608 7799
Ahmedabad: 6671 2600
Mumbai: 6779 9489 / 6779 9466
Kolkata: 6636 6044 / 6636 6037
Chennai: 6616 4111 / 6616 4068
Lucknow: 2223 7472 / 2223 7390
Bangalore: 6725 1250 / 6724 7222

--- ASPIRE PORTAL---
https://ilpcms.tcs.com/aspire/

For Aspire: Contact Mr. Arun Giri
+91 471 6629400, Extn: 2536
arun11.g@tcs.com

Sample documents for tcs joinees

These documents are not mine a friend send it to me for just an idea of how the things are to be done, preparing document is the worst part of joining tcs its very irritating if  you have any confusion see if i can help here is the link 
TCS sample documents for freshers

list of documents to be carried to ilp

Original n Attested Copies of these :
1. Xth and XIIth Markscards.
2. All semester Markscards.
3.Degree Certificate/Provisional Degree Certificate/Course Completion Certificate
4. Birth Certificate [In case if not available make a affidavit of Rs. 20]
5. Valid Passport [If any]
6.Offer Letter n Joining Letter
7. PAN Card
8. Medical Certificate[Dont forget to sign and seal the photo]

**12 Passport size Photos

**Service agreement on Rs. 100 stamp paper or e-stamp[for karnataka]
Surety - Income Tax Payee / Person posessing Landed property/ Fixed Deposit of Rs. 50k to TCS in a bank

In case of Surety being an IT payee following docs to be submitted[Attested by Gazetted Officer]
*Pan Card
*IT returns/Saral/Form 2D/Form 16/Form 12B
*Surety Verification Form/ Valid Passport Copy

**No Criminal Offence Affidavit on Rs. 100 stamp paper or e-stamp[for karnataka]
Notarised by a Lawyer

** NSR Card printout (not mandotary but carry)

** Acceptance of Joining

** Filled BGC Form[With photo in appropriate place]

Docs required for BGC form[Signed and Self attested]:

1.ID Proof Document [Valid Passport/DL/PAN Card/Voter ID/College ID attested by HOD/Princi/TPO]

2.Address Proof Document
-Proof for Present & Permanent address to be attached
-Provide Seperate Proof,if address is different

[Ration Card/ Elec Bill / Telephone bill /Valid Passport]
OR
[House Lease Agreement and Related Docs]
OR
[Hostel Allotment Letter from college is staying in College hostel]

3.Highest Degree Certificate/Provisional Degree Certicate [Another copy which is self attested other than those attested by gazetted officer]

4.Highest Degree Marks sheets of all exams [Another copy which is self attested other than those attested by gazetted officer]

5.Birth Certificate[As asked again in BGC Form]

6.Affidavit to explain Gap in education [If any] Notarized Rs. 20 Stamp Paper

Note :If ur present address/Address of Longest stay in 7 yrs /Permanent Address is Mumbai/Thane City/Thane Rural /Pune, submit CID form,2 Photos with name written on back of each photo and Address Proof [Ration Card/ Elec Bill / Telephone bill ]

I think I have mentioned all the documents. If i have left out any documents plz mention in comments

Finaly got date of joining from TCS, its 28 march @ ilp hyderabad

I have been a little busy for last 3 months doing all dose boring training stuffs, ppt ,study materials. I had joined Lnt Infotech on 28 dec and after that life became monotonous. Same boring office works living like a robot which has been programmed to do all sort of thing except getting some quality time for myself. I always thought life was going to be much easy and would relax after getting a job in the IT industry but actually its not exactly the case  here or say its a destiny of a fresher to be doomed in this big bad corporate world. Anyways its the end of chapter one of my career signing off from Lnt  and signing in to TCS hyderabaad looking forward to ilp days, have heard its something like a paid holiday .This is something which i m looking for ryt now. I was looking for some before hand experience from my senior batches of ilp Hyderabad googled it but i think they are not quite active as compared to their counterparts from other ilps looking  forward to TCS and off course hyderabadi biryaani  ;)