The rest of this article will refer to variables. But each one could be a parameter except for the variables with expressions. This is because an expression will over write any value passed in. A common need is to save a file with a date appended to it. This can be done with an expression and a variable. The first example is going to be using one variable without the best practices applied.
Of course we are going to need a file system task to save the file for us. One of the nice features of the file system task is the fact that the rename function can rename and move a file.
You simply set the source and destination to a different location. You should never need two file system tasks back to back, with one doing the move and the other doing the rename. The first thing we are going to do is create a file connection in the connection manager of a package.
The source in the File system task will be set to this connection. We could use a variable to pass this name in if we needed. In this example the destination is the important part. We will need a variable on the package also. I will create a variable called strFileName.
It is always a best practice to create variables with the first few letters of the name describing the data type and camel case the rest of the variable name. Here is a list of some data types and the extensions to use. Now we set the properties of the variable.dynamic connection manager in SSIS - SSIS Tutorial Part 10.1
Set the property EvaluateAsExpression to true. Then click on the expression ellipse and set the expression to:. Notice the double slashes.
These are necessary due to escape characters. Also notie the double quotes around the literals. Then we simple use three functions. This is an easy way to save a file with the date.Last week, I demonstrated a simple way to create variables and how to write a value to those variables using an execute SQL task. Once a variable is populated, what can you do with it? As a recap, last week I used an Execute SQL task to pull the max value for a date key that is copied to an archive table the destination.
The task then stores the value it returns in a variable.
Parameterizing Database Connection in SQL Server Integration Services
After selecting or creating the connection manager, set the data access mode to SQL Command. In my example, I am using a basic select statement that is returning all the fields that I want to archive. The process date value is being stored in a variable, so the first step in accessing that variable is to add a question mark in the query in place of the variable name that you would typically use when running the statement in SSMS.
The question mark in the SQL command is referred to as a parameter. Parameters are mapped to variables so that the values can be used in the SQL commands. Click the Parameters button to the right of the command text field. This opens the parameter mapping editor. In this package, I am only using one, so I only have one mapping to define. If I were using multiple parameters in the query, each one would show in the editor. Pay attention to the order of your parameters.
This is extremely important. When you map multiple parameters, they are mapped in the order in which they fall in the statement.
The statement would look like this…. When mapping the parameters, the first one would have to be the variable that contains the start date and the next one would be the variable that contains the end date. They have to mapped in the order in which they fall. In the editor, in the variables column, open the drop down menu and select the variable you need.
Click OK to close the mapping editor. In fact, when working on some older versions of Visual Studio, clicking the Preview button or the Parse Query button may return an error. Now that the parameters are mapped, when the package is executed, the Execute SQL task will return the process date key value and store it in the variable.Although it may seem like a lot of steps, it's a one-time setup per environment and makes your SSIS projects very portable and allows for easier manageability of dynamic values that change routinely.
This functionality is useful for any number of things, frequently for specifying different values between Dev, QA, and Prod environments. Note that these SSIS environment variables are a different thing than Windows environment variables, although similarly named. They're also different from "regular" variables inside an SSIS package. This technique is applicable to SQL Server and up, and only to the project deployment mode i. Will need to manually specify which Environment to use at execution time when running in this on-demand manner.
Associate the job to the appropriate Environment so it automatically detects values which have been set. First thing to do is determine what elements of the package you wish to be able to vary at runtime. In the example below I have 2 project-level parameters that signify a date range.
Sidenote: in the real world, this generic name of "data extract As you'll see below, the SSIS environment variables on the server are shared across all projects, so that may influence your naming conventions if you have numerous projects to manage. And here's an example of how a source query in my data flow has been associated to the project parameters:. Note that there's a couple of different ways to handle changes to connection strings as you migrate from Dev to QA to Production.
This describes one way to handle connections by grouping them with parameters. In this example I've parameterized the connecting string itself. You can parameterize individual properties like server name, user name, catalog, if you prefer. This connection string is using Windows authentization so it's not set to sensitive if it were a password you'd want to set it to sensitive so that it's encrypted. I do like to set it to be Required which ensures it will be set in the SSIS Catalog before the package can be executed on the server.
For deploying to other environments like Prod, where you may need to hand off the deployment to someone else, I typically make use of the ISDeploymentWizard tool instead. Environments are usually called Dev, QA, Prod, that sort of thing, but they could of course be used differently in some situations.
Modify any of the values if different on the server than were used in SSDT. At this point we have an SSIS environment available with variables specified that coincide with our parameters. Now we're ready to let the project know that the environment exists and which one to use, if there are multiple environments on the same server. On the parameters page, we can associate each parameter for the project to the environment variable that was set up. In this example I kept the scope at the project level, but you can set them at the individual package level when appropriate.
I think a little bit background will be beneficial to understand the Parameter concept. Here I will explain it in the context of comparing with Variables.
To fully grasp the Parameter concept, you might need to look up for the new Project Deployment Model, Environment, Build Configuration as well. With SSIS priorif we need to pass any external values to the package before the execution as we all do all the timeI normally use configuration file or a couple of other ways.
Say we have a file server, which will be used to access a shared file, I will use variable to store the server name, and expose this variable to the configuration file. If the actual file server is changed dev env to test env etc. Everything looked good, but there are a couple of things that I always ask myself why and could not figure out why:. Why does SSIS allow to expose all the other variable properties? Why does SSIS not have "private" variable? By "private" I mean when I chose the variables to configure, the "private" ones just did not get shown on the pick list.
The SSIS package could have dozens of variables, for the internal value-holders, what's the point to expose them? Why I have to scroll all the way to find the only one I need to expose? Parameters and connection managers are exposed automatically in SSIS catalog which can be configured, nothing else previously available via configuration files can be configured in Project Deployment Model The world is much cleaner.
Inside SSIS package, parameters can be used in the same way as variables in terms of building up expressions. Why do we need to change a value which is passed in from external? If we have to, pass the value to an variable, and do the changes there. Parameter is only available in the Project Deployment Model, and it provides the only mechanism for passing values from external to SSIS packages in this model.
Where Variables could be thought as private variables, which are used internally, external world does not need to know anything about it.
FYI, in short, variable's value can be changed during the runtime, but parameter cannot. Lets say you deploy an SSIS package into two integration catalog environments, one which is configured for prod server and another which is configured for test server:.
Then your ServerName 'parameter' will be set in prod with prod server address and in test environment to contain test server address. If any variable in your ssis package needs a runtime value say the variable is used to set a connection at run time for prod or test servers respectively then the variable will use the parameter from above to find the right server to connect to.
There are two types of parameters based on how you've configured your solution in Visual Studio: Project parameters or Package parameters. Project parameters are accessible to all packages in the project. Parameters are using send data from outside of the package like usernames, passwords or connectionstrings etc.
Variables are using inside of the package. It means you can define a variable in one of your SSIS package and use it in package level. Learn more. Asked 7 years, 1 month ago.What types of objects can invoke an expression?
Developing a static SSIS package is a relatively easy task, but the SSIS package cannot be used without modification in development, test and production environments. The name of the server, database name, source file folder location, the business conditions, etc. SSIS expressions help us to achieve this functionality. Let's learn about some of the basic functionality for expressions and their usage.
An expression is a code snippet which returns a value. This could contain symbols, identifiers, literals, functions and operators. An expression can be simple or complex enough to hold multiple expressions.
They are very handy to dynamically update properties at run time.
Expressions are based on the expression language and expression evaluator. Once the expression is complete, the expression evaluator will parse the expression to validate the expression rules. Expression builder is a tool which helps us build an expression. This tool can be invoked from the expression property of a Task or Container. Also, this tool is available for the conditional split transformation and derived column transformation. The Expression Builder will list all available variables and parameters based on the scope.
This is very useful for an SSIS developer who can drag and drop, then build the expression based on variables, functions and constants. A variable value can be derived based on the expression.
Common Examples of SSIS Expressions and Variables
Another variable "ProductFileName" has been defined to have the absolute value of the file name. As the root folder has already been stored in another variable, the value of the product data file can be derived as shown below. As per the image below, the value of the variable "ProductFileName" can be derived from the variable ParentFolder.
This is done by clicking the button next to the variable. The ParentFolder variable can be dragged and dropped from the variable list and the name of the file can be added in the expression.
The expression can be validated using the "Evaluate Expression" button. The expression will be validated and the value will be displayed as shown below. As the name of the database and the server will be different based on the target environment, two new variables have been created to store the values.
Now the ConnectionString can be built at run time based on the value of these variables. Select the Connection Manager and select the property window to add an expression. On the expression property, click on the button. This will open another dialog box to choose the property for the Connection Manager. Select "ConnectionString" as the property and click on the expression button.
This will load the Expression Builder to build the expression. By adding the values of the server and database variables a connection string can be built as shown below.
Let's assume that we have a root folder and we would like to iterate through the files in the folder to look for the CSV file then load the data into the table. The ForEach Loop container is one of the best options to accomplish this task. Let's see how the expression can be used to setup the folder and file extension at run time. The location of the folder may vary based on the environment Dev, Test and Prodhence it is preferable to setup the location of the folder and the file extension at run time.
Once the expression has been added, the expression can be seen in the main window as shown below. We will be using the AdventureWorks database.
Execute SQL Task in SSIS: Output Parameters vs Result Sets
A SQL task has been setup to count the number of products based on a given product category name. A variable has been created to store the product category name.Note that this article is the fifth article in the SSIS feature face to face series, which aims to remove confusion and to illustrate some of the differences between similar features provided by SQL Server Integration Services.
To add a parameter into a SQL statement you must use a parameter marker which differs based on the connection type. To add a parameter mapping, we must click on the Add button, since we have on specified one parameter in the SQL command then we should add only one mapping.
When we click on the Add button, one line is added to the grid as shown in the image below:. Parameter Name: The name of the parameter, the naming convention depends on the connection type:.
Connection type. When it comes to output parameters, they are used to store values that can be set at any part of the SQL command, they have the same concept of the stored procedure output parameters. There are many types of result sets:.
To store the result set into a variable, we must configure the variable mapping within the Result Set tab. In the Result Set tab, you must specify the result name and the variable that you want to map to. If the result set type is Single rowthe result name must be the column name or the column position in the column list.
If the result set type is Full result set or XML, you must use 0 as the result set name. When it comes to variable mapping each type of result set must be mapped to specific variable data types:.
But, when the result set is stored within a variable of type System. Objectthe variable can be consumed using:. In general, each one of these options has its own use cases even if there are some similarities.
In this section, I will try to illustrate the differences and similarities between these two options. If we need to store values from different SQL command we cannot use Result Sets, while output parameters can do the trick:. In case that we need to retrieve a value from a query located in the middle of the whole SQL statement and reuse this value within the same SQL statement, we need output parameters:.
Dim dt As Data. Dim ds As Data. Variables " Recordset ". ValueDataSet. Tables 0. Dim dt As DataTable. Fill dtDts. Variables " User : : transactionalRepDBs ". Dim xdoc As New XmlDocument. Author Recent Posts. Hadi Fadlallah. He has been working with SQL Server for more than 10 years. View all posts by Hadi Fadlallah. Latest posts by Hadi Fadlallah see all. Param1, Param2, …. DataTable Dim ds As Data. Dim xdoc As New XmlDocument xdoc.This will bring up your variables window on the left hand side of your screen.
You should be able to tab between it and the Toolbox. You may have to pin it to your screen first. I have already created some variables in the screenshot above. To create a variable, first decide on the scope of the variable, whether it is the entire package, a container or a specific task.
I find it easier to manage variables having them all in one place. In this case select the canvas of the Control Flow which will permit you to scope the variable to the entire package. Then create the variable by clicking on the Add Variable button at the top of the Variables window.
Give your variable a Name, a Data Type and a Value. In this case we are working with EndDate, and although you would want to set it as Date, there are some compatibility issues when using the Date data type for a variable and then pulling into a SQL parameter.
I have found it is best to set the date as a string and then manipulate it from there. Set your EndDate attributes as shown, with the Scope being the name of your package. Double click on it and set the following properties:. Even if you are using the same Variable multiple times, you still need to enter them separately on the Parameter Mapping tab, once for each time they appear in the SQL Statement.
This is the only way to identify which parameter is being used for which question mark. Parameters are made much easier in Hi, Thanks for the information given above. Its useful.
Can you please let me know when to use single row set and full row set in Execute SQL task? Hi Karan, Single row set is when you only ever expect one row returned. Full row is when you expect multiple rows.
Is there a similar approach that would create a variable that holds a list of values? I need to hit one database to get a list of product codes returnedand use that list as a filter in another query on another database via a different connection managerthe resulting query uses an IN operator as the filter — eg.