Technical Insights: Azure, .NET, Dynamics 365 & EV Charging Architecture

Month: January 2011

Tag Replacement using Regex in .NET

This snippet of code shows how to do Synchronisation or HTML tag replacement

-My problem is i want to synchronise of tags between 2 HTML document

Issue

-Source.htm

my source.htm has this tag

<xml id=STATIC_CRITERIA_>

  <fields>

    <field fieldID=OPEN_FLAG displayType=checkboxGroup searchType=checkboxGroup underlyingType=int />

    <field fieldID=PARTITION displayType=dropdown searchType=profile profileID=SU_PARTITIONS underlyingType=int />

    <field fieldID=TEMPLATE_IND displayType=checkbox searchType=checkbox underlyingType=int />

    <field fieldID=INCLUDE_DELETED displayType=checkbox searchType=checkbox underlyingType=string />

  </fields>

</xml>

 -Target.htm has this tag

<xml id=STATIC_CRITERIA_>

</xml>

So now the problem is how do I fill the gap in XML tag in target.htm with the value from mySource.htm. We can do this using regex and it’s very simple

 

  string originalDocument = Load(“c:\\MySource.htm”);

                string syncDocument = Load(“c:\\Target.htm”);

 

                MatchCollection mc = Regex.Matches(originalDocument, “<xml([ ]?.*?)>(.*?)</xml>”, RegexOptions.Singleline | RegexOptions.IgnoreCase);

 

                foreach (Match m in mc)

                {

                    string token = “<xml{0}>”;

                    syncDocument = Regex.Replace(syncDocument, String.Format(token, m.Groups[1].Value) + “(.*?)</xml>”,

                                                               String.Format(token, m.Groups[1].Value) + m.Groups[2].Value + “</xml>”,

                                                               RegexOptions.Singleline | RegexOptions.IgnoreCase);

                }

 MatchCollection is used to return all the instances of that regular expression (e.g you might have multiple XML tags with different ID)

What does this tag means

“<xml([ ]?.*?)>(.*?)</xml>”

 ([ ]?.*) means that I don’t care whatever after it (e.g it can be ID or attributes etc). this is the first parameter that we stored on variable

(.*?) means that whatever inside the tag are captured into the second parameter that we stored on variable

You can access the first variable (e.g any attributes after the XML) by doing

m.Groups[1].Value

you can access the value inside the xml bracket by using

m.Groups[2].Value

so what  contains in

m.Groups[0].Value

it contains the whole xml tag that we extracted using regex

 then we can use regex.replace method to replace the tag in target html. When you replace the tag you need to replace the whole xml tag. You can’t just replace the inner part of it

   foreach (Match m in mc)

                {

                    string token = “<xml{0}>”;

                    syncDocument = Regex.Replace(syncDocument, String.Format(token, m.Groups[1].Value) + “(.*?)</xml>”,

                                                               String.Format(token, m.Groups[1].Value) + m.Groups[2].Value + “</xml>”,

                                                               RegexOptions.Singleline | RegexOptions.IgnoreCase);

                }

Recovering a corrupt iTunes DB on iphone

You need to explore the file in your iphone, you can use SSH or you can use this tool i-FunBox (it’s free at http://i-funbox.com/)

Please navigate to

/private/var/mobile/Media/iTunes_Control/iTunes

and rename folder iTunes_control to iTunes_control2 (or BAD)

When you connect to iTunes then it will ask you to configure your ipod then

I’ve renamed it, connect to iTunes and iTunes will recreate a new iTunes_Control database (hence I deleted iTunes_Control2 folder)

using BCP to transfer a large amount of data in SQL Server

I would like to transfer hundred millions of records between table in different database server. I tried to use DTS export/import and it’s not fast enough for my needs but i forget that there is a BCP command in SQL which is SQL Server format file.

The speed in my local machine is (22795.13 rows per sec)

Sample of the command: (You need to run it in command prompt), you can find bcp.exe in folder (C:\program files\Microsoft SQL Server\100\Tools\Binn) – The 100 is for SQL Server 2008, for SQL server 2005 it’s 90

Sample

1. You need to generate the BCP File from the source table

bcp MyDatabase.dbo.MyTable out C:\BCP_MyTable -n -S localhost -T -e[BCP_MyTable_ERROR]

*Using -T is for trusted connection

2. You need to import the BCP file to the destination table

bcp MyDatabase.dbo.MyTable in C:\BCP_MyTable -n -S localhost -T -e[BCP_MyTable_ERROR]

for further command line reference click here

*UPDATE:

you can configure your server to to reduce the amount of transaction log during bulk copy/insert transaction by executing

EXEC SP_DBOPTION MyDatabase, ‘SELECT INTO/BULKCOPY’, TRUE

bcp MyDatabase.dbo.MyTable in C:\BCP_MyTable /b 20000 -n -S localhost -T -e[BCP_MyTable_ERROR]

What I did was to add extra parameter of /b and the number 20000 (you should play around with the number to see the best one fit your situation) after it means the number of the records per transaction. Please be careful if you don’t put /b parameter, sql server by default will commit all the records at once. but if you put /b parameter then it will commit the transaction per x amount of records specified. If you transfer large data, you shouldn’t commit all at once because it will take sometime. In my case I transferred 18 millions of records

I’d recommend you to save the BCP file and copy the file over if it’s in different server because you need to be careful with the bandwidth of the network and the risk if the network connection is interrupted

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