Showing posts with label control flow tasks. Show all posts
Showing posts with label control flow tasks. Show all posts

Sunday, August 28, 2016

For Each Loop Container in SSIS

For Each Loop Container in SSIS:

Why For Each Loop Container Task is Use ?
  • For Each Loop container is falls under container and looping tasks
  • Use containers like the For Each Loop and For Loop to execute a set of tasks multiple times.
  • For example, you can loop over all the tables in a database, performing a standard set of operations like updating index statistics.
  • In short when we have to iteratively execute set of task we will insert all those task under For Loop Container and set the values accordingly
  • The for each loop container acts as a repeating control flow in a package. Its operations are similar to work of For each keyword in any advanced programming language. We have a definite type of enumerator for each type of objects.
  • Loop implementation in the For Each Loop Container is similar to the Foreach looping concept in various programming languages.
The Foreach Loop container defines a repeating control flow in a package. The loop implementation is similar to Foreach looping structure in programming languages. In a package, looping is enabled by using a Foreach enumerator. The Foreach Loop container repeats the control flow for each member of a specified enumerator.
Enumerator is nothing but an iterator where an object that enables a programmer to traverse a container
SQL Server Integration Services provides the following enumerator types:
  1. Foreach File Enumerator: It enumerates files in a folder. The plus point here is it can traverse through subfolders also.
  2. Foreach Item Enumerator: It enumerates items in a collection. Like enumerating rows and columns in an Excel sheet.
  3. Foreach ADO Enumerator: Useful for enumerating rows in tables.
  4. Foreach ADO.NET Schema Rowset Enumerator: To enumerate through schema information about a data source. For example, to get list of tables in a database.
  5. Foreach From Variable Enumerator: Used to enumerate through the object contained in a variable. (if the object is enumerable)
  6. Foreach NodeList Enumerator: Used to enumerate the result set of an XML Path Language (XPath) expression.
  7. Foreach SMO Enumerator: It enumerates through SQL Server Management Objects (SMO) objects.
How For Each Loop Container Task is look like ?
This is Second task in tab itself !!
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Drag this out in your development plane
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Features of For Each Loop Container Task
The following diagram shows a Foreach Loop container that has a File System task. The Foreach loop uses the Foreach File enumerator, and the File System task is configured to copy a file. If the folder that the enumerator specifies contains four files, the loop repeats four times and copies four files.