Tag - Interview

Create SSIS Data Flow Task Package Programmatically
Jul 27, 2020

In this article, we will review how to create a data flow task package of SSIS in Console Application with example. Requirements Microsoft Visual Studio 2017 SQL Server 2014 SSDT Article  Done with the above requirements? Lets start by launching Microsoft Visual Studio 2017. Create a new Console Project with .Net Core.  After created new project provide proper name to it. In Project Explorer import relevant references and ensure that you have declared namespaces as below: using Microsoft.SqlServer.Dts.Pipeline.Wrapper; using Microsoft.SqlServer.Dts.Runtime; using RuntimeWrapper = Microsoft.SqlServer.Dts.Runtime.Wrapper;   To import above namespaces we need to import below refrences.   We need to keep in mind that, above all references should have same version.   After importing namespaces, ask user for the source connection string, destination connection string and table that will be copied to destination. string sourceConnectionString, destinationConnectionString, tableName; Console.Write("Enter Source Database Connection String: "); sourceConnectionString = Console.ReadLine(); Console.Write("Enter Destination Database Connection String: "); destinationConnectionString = Console.ReadLine(); Console.Write("Enter Table Name: "); tableName = Console.ReadLine();   After Declaration, create instance of Application and Package. Application app = new Application(); Package Mipk = new Package(); Mipk.Name = "DatabaseToDatabase";   Create OLEDB Source Connection Manager to the package. ConnectionManager connSource; connSource = Mipk.Connections.Add("ADO.NET:SQL"); connSource.ConnectionString = sourceConnectionString; connSource.Name = "ADO NET DB Source Connection";   Create OLEDB Destination Connection Manager to the package. ConnectionManager connDestination; connDestination= Mipk.Connections.Add("ADO.NET:SQL"); connDestination.ConnectionString = destinationConnectionString; connDestination.Name = "ADO NET DB Destination Connection";   Insert a data flow task to the package. Executable e = Mipk.Executables.Add("STOCK:PipelineTask"); TaskHost thMainPipe = (TaskHost)e; thMainPipe.Name = "DFT Database To Database"; MainPipe df = thMainPipe.InnerObject as MainPipe;   Assign OLEDB Source Component to the Data Flow Task. IDTSComponentMetaData100 conexionAOrigen = df.ComponentMetaDataCollection.New(); conexionAOrigen.ComponentClassID = "Microsoft.SqlServer.Dts.Pipeline.DataReaderSourceAdapter, Microsoft.SqlServer.ADONETSrc, Version=14.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; conexionAOrigen.Name = "ADO NET Source";   Get Design time instance of the component and initialize it. CManagedComponentWrapper instance = conexionAOrigen.Instantiate(); instance.ProvideComponentProperties();   Specify the Connection Manager. conexionAOrigen.RuntimeConnectionCollection[0].ConnectionManager = DtsConvert.GetExtendedInterface(connSource); conexionAOrigen.RuntimeConnectionCollection[0].ConnectionManagerID = connSource.ID;   Set the custom properties. instance.SetComponentProperty("AccessMode", 0); instance.SetComponentProperty("TableOrViewName", "\"dbo\".\"" + tableName + "\"");   Reinitialize the source metadata. instance.AcquireConnections(null); instance.ReinitializeMetaData(); instance.ReleaseConnections();   Now, Add Destination Component to the Data Flow Task. IDTSComponentMetaData100 conexionADestination = df.ComponentMetaDataCollection.New(); conexionADestination.ComponentClassID = "Microsoft.SqlServer.Dts.Pipeline.ADONETDestination, Microsoft.SqlServer.ADONETDest, Version=14.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91"; conexionADestination.Name = "ADO NET Destination";   Get Design time instance of the component and initialize it. CManagedComponentWrapper instanceDest = conexionADestination.Instantiate(); instanceDest.ProvideComponentProperties();   Specify the Connection Manager. conexionADestination.RuntimeConnectionCollection[0].ConnectionManager = DtsConvert.GetExtendedInterface(connDestination); conexionADestination.RuntimeConnectionCollection[0].ConnectionManagerID = connDestination.ID;   Set the custom properties. instanceDest.SetComponentProperty("TableOrViewName", "\"dbo\".\"" + tableName + "\"");   Connect the source to destination component: IDTSPath100 union = df.PathCollection.New(); union.AttachPathAndPropagateNotifications(conexionAOrigen.OutputCollection[0], conexionADestination.InputCollection[0]);   Reinitialize the destination metadata. instanceDest.AcquireConnections(null); instanceDest.ReinitializeMetaData(); instanceDest.ReleaseConnections();   Map Source input Columns and Destination Columns foreach (IDTSOutputColumn100 col in conexionAOrigen.OutputCollection[0].OutputColumnCollection) {     for (int i = 0; i < conexionADestination.InputCollection[0].ExternalMetadataColumnCollection.Count; i++)     {         string c = conexionADestination.InputCollection[0].ExternalMetadataColumnCollection[i].Name;         if (c.ToUpper() == col.Name.ToUpper())         {             IDTSInputColumn100 column = conexionADestination.InputCollection[0].InputColumnCollection.New();             column.LineageID = col.ID;             column.ExternalMetadataColumnID = conexionADestination.InputCollection[0].ExternalMetadataColumnCollection[i].ID;         }     } }   Save Package into the file system. app.SaveToXml(@"D:\Workspace\SSIS\Test_DB_To_DB.dtsx", Mipk, null);   Execute package. Mipk.Execute(); Conclusion In this article, we have explained one of the alternatives for creating SSIS packages using .NET console application. In case you have any questions, please feel free to ask in the comment section below.

DELETE and UPDATE CASCADE in SQL Server foreign key
Jul 20, 2020

In this article, we will review on DELETE AND UPDATE CASCADE rules in SQL Server foreign key with different examples. DELETE CASCADE: When we create a foreign key using this option, it deletes the referencing rows in the child table when the referenced row is deleted in the parent table which has a primary key. UPDATE CASCADE: When we create a foreign key using UPDATE CASCADE the referencing rows are updated in the child table when the referenced row is updated in the parent table which has a primary key. We will be discussing the following topics in this article: Creating DELETE CASCADE and UPDATE CASCADE rule in a foreign key using T-SQL script Triggers on a table with DELETE or UPDATE cascading foreign key Let us see how to create a foreign key with DELETE and UPDATE CASCADE rules along with few examples.   Creating a foreign key with DELETE and UPDATE CASCADE rules Please refer to the below T-SQL script which creates a parent, child table and a foreign key on the child table with DELETE CASCADE rule.   Insert some sample data using below T-SQL script.   Now, Check Records.   Now I deleted a row in the parent table with CountryID =1 which also deletes the rows in the child table which has CountryID =1.   Please refer to the below T-SQL script to create a foreign key with UPDATE CASCADE rule.   Now update CountryID in the Countries for a row which also updates the referencing rows in the child table States.   Following is the T-SQL script which creates a foreign key with cascade as UPDATE and DELETE rules. To know the update and delete actions in the foreign key, query sys.foreign_keys view. Replace the constraint name in the script.   The below image shows that a DELETE CASCADE action and UPDATE CASCADE action is defined on the foreign key. Let’s move forward and check the behavior of delete and update rules the foreign keys on a child table which acts as parent table to another child table. The below example demonstrates this scenario. In this case, “Countries” is the parent table of the “States” table and the “States” table is the parent table of Cities table.   We will create a foreign key now with cascade as delete rule on States table which references to CountryID in parent table Countries.   Now on the Cities table, create a foreign key without a DELETE CASCADE rule. If we try to delete a record with CountryID = 3, it will throw an error as delete on parent table “Countries” tries to delete the referencing rows in the child table States. But on Cities table, we have a foreign key constraint with no action for delete and the referenced value still exists in the table.   The delete fails at the second foreign key.   When we create the second foreign key with cascade as delete rule then the above delete command runs successfully by deleting records in the child table “States” which in turn deletes records in the second child table “Cities”.   Triggers on a table with delete cascade or update cascade foreign key An instead of an update trigger cannot be created on the table if a foreign key on with UPDATE CASCADE already exists on the table. It throws an error “Cannot create INSTEAD OF DELETE or INSTEAD OF UPDATE TRIGGER ‘trigger name’ on table ‘table name’. This is because the table has a FOREIGN KEY with cascading DELETE or UPDATE.” Similarly, we cannot create INSTEAD OF DELETE trigger on the table when a foreign key CASCADE DELETE rule already exists on the table.   Conclusion In this article, we explored a few examples on DELETE CASCADE and UPDATE CASCADE rules in SQL Server foreign key. In case you have any questions, please feel free to ask in the comment section below.

Table partitioning in SQL
Jun 10, 2020

What is table partitioning in SQL? Table partitioning is a way to divide a large table into smaller, more manageable parts without having to create separate tables for each part. Data in a partitioned table is physically stored in groups of rows called partitions and each partition can be accessed and maintained separately. Partitioning is not visible to end-users, a partitioned table behaves like one logical table when queried. Data in a partitioned table is partitioned based on a single column, the partition column often called the partition key. Only one column can be used as the partition column, but it is possible to use a computed column. The partition scheme maps the logical partitions to physical filegroups. It is possible to map each partition to its own filegroup or all partitions to one filegroup.

The common do’s and don’ts of interview body language
Jan 02, 2020

To make the whole concept clear to you, we thought of giving you a tabular comparison of some of the major common dos and don’ts of interview body language. Keep reading to make the most of these powerful body language tips.   The Dos Enter confidently: You must enter confidently since the recruiters even check with the reception about your body language. They believe in observing from the beginning and noticing all the changes. First impressions do matter and, in some cases, they matter the most. Don’t be too nervous and try to breathe deeply to calm yourself.    A firm handshake: As mentioned earlier, a firm handshake makes an interviewer feel your enthusiasm and confidence. But remember to let go at the right time. A firm handshake makes them confident about your self-assured personality. Sit straight: Keep your back straight (not too stiff) and maintain your posture in such a way that your legs are firmly placed. Lean in towards the interviewers to give an impression of you being interested in what they speak. Maintain eye contact: It is of utmost importance that you look directly into the eyes of the person who asks you questions. Make eye contact with every panelist, to look confident and convincing. The average time should be 10-12 seconds. If you get nervous, look at their nose for a few seconds Smile: The panel never wants someone who is grim and grumpy. While it is necessary to take questions seriously, it is also important to show them the light side of you. Smile and make them aware of your pleasant and agreeable persona. Also, it makes you look less nervous, so it is a bonus! Pay attention to your hands:  Hands should not ever come in between the direct line of vision between you and the interviewer. Closing them to form a fist, fidgeting or bending your knuckles are a few things that must be avoided. Focus on making gestures with hands and if that is not possible, then start taking notes. Writing will not let your hands be idle and they won’t attract any undue attention. Additional things to do:  Keep your phone on silent/flight mode. Remember to carry a pen in your pocket. Place your feet firmly on the ground to make the process of answering the questions easier.     The Don’ts; Come up as overconfident: Overconfidence is a big no when it comes to interviews. Interrupting the recruiters believing that you know the company better than them and trying to behave overconfidently are the things which will make you look negative and arrogant. Be polite, humble and use your curiosity judiciously. This is a very important point in the common dos and don’ts of interview body language. A loose handshake: A weak handshake shows your lack of confidence and enthusiasm. You must try and mirror the handshake of your interviewer if you want to look active and confident. Don’t put too much pressure too because it can make you look aggressive. Slouch/bend too much: If you lean outwards too much or keep your shoulders bent, then it’s time for you to correct it before you appear for an interview. There is nothing more annoying than a lazy candidate who looks insecure all the time. Stare blankly: There is a difference between eye contact and staring. If you continue to maintain eye contact for more than 15 seconds at a go, then it would surely make your interviewer uncomfortable. Staring at the other things in the cabin shows that you are a distracted personality. Be the focused person they are looking for. Toying with objects: If you have a habit of clicking the pen repeatedly, adjusting your hair too often and touching your nose all the time, then you should seriously practice some ways to stop these. All of these actions look gross and interviewers would be irritated with them. You are there to impress them, not annoy them. Fidgeting or drumming your fingers on the table: These habits are signs of restlessness. Changing the position of your hands, legs or even fingers too much can seriously affect the continuity of the interview process. The last thing any company would want is a person who is so distracted that he disturbs everyone around him. Fidgeting affects everyone around you, so try to keep it in check for a positive interview experience. Additional things you should never do : Chewing a gum, checking the clock on your phone, taking a call, trying to be over-friendly/personal or going in for a hug. Maintain the decorum of your interview, as this is a thumb rule in the common dos and don’ts of interview body language.