Today, I am going to explain SSIS For Each Loop Task. I am sure that it will be
easy to configure SSIS Package with Foreach Loop task, after you read this article.
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.
Many times, user asks that I want to process all files from my folder to database.
This is my answer to all of those users. SSIS comes up with For Each Loop which
did the same.
Now I'm assuming that you're familiar with using the SQL Dev Studio tools and building
basic packages. If this isn't the case, I recommend working your way through the
Integration Services using my earlier posts.
1. SSIS Foreach Loop Container - General: Here
we need to assign unique name to this container and also we can specify brief description,
so we will get idea why we need to design this container.
2. SSIS Foreach Loop Container - Collection:
Use the Collection page of the Foreach Loop Editor dialog box to specify the enumerator
type and configure the enumerator.
Select the enumerator type from the list. This property has the options listed as
follows:
- Foreach File Enumerator: Enumerate
files
- Foreach Item Enumerator: Enumerate
values in an item
- Foreach ADO Enumerator: Enumerate
tables or rows in tables
- Foreach ADO.NET Schema Rowset Enumerator:
Enumerate a schema
- Foreach From Variable Enumerator:
Enumerate the value in a variable
- Foreach Nodelist Enumerator: Enumerate
nodes in an XML document
- Foreach SMO Enumerator: Enumerate
a SMO object
Let me explain with Foreach File Enumerator
We can use this Foreach File enumerator to enumerate files in a folder.
The content of the folders and subfolders that the Foreach File enumerator enumerates
might change while the loop is executing because external processes or tasks in
the loop add, rename, or delete files while the loop is executing. This means that
a number of unexpected situations may occur:
In Folder option, provide the path of the root folder to enumerate.
In Files option, specify the files to enumerate.
If wildcard characters are specified in the Files option, then the fully-qualified
paths that are returned match the filter.
- Fully qualified: Select to retrieve
the fully qualified path of file names.
- Name and extension: Select to retrieve
the file names and their file name extensions.
- Name only:Select to retrieve only
the file names.
3. SSIS Foreach Loop Container - Variable Mappings:
Use the Variables Mappings page of the Foreach Loop Editor dialog box to map variables
to the collection value. The value of the variable is updated with the collection
values on each iteration of the loop.
Variable: Select an existing variable, or click <New variable...>
to create a new variable.
Index: If using the Foreach Item enumerator, specify the index
of the column in the collection value to map to the variable. For other enumerator
types, the index is read-only.
Once we configured, For Each Loop container, Lets add the process
that we want. Here what I am going to do is:
NOTE: We can add any other tasks to this container. I took
Data flow process, as its already explained by this BLOG.
Here lets see the logical scenario of For Each Container Task.
First, From the selected folder, fetch all the files and assign file path to the
variable.
Second, For
Data Flow Process, process the file from the folder and execute data flow.
NOTE: For Data Flow Process, we need to assign Connection from variable. ( as we
assigned variable after each loop, we need to process new file from the folder).
So How can we configure File connection to use new file?
That's it. This is what we need to design for "For Each Loop".
Let me know if there is any difficulties you have to design this package.
Republished from SQL Yoga [33 clicks].
Read the original version here [32134 clicks].