Astera Data Stack
Version 8
Version 8
  • Welcome to Astera Data Stack Documentation
  • Release Notes
    • Astera 8.0 - What's New, What's Fixed, and What's Improved
    • Astera 8.0 - Known Issues
    • Astera 8.1 - Release Notes
    • Astera 8.2 Release Notes
    • Astera 8.3 Release Notes
    • Astera 8.4 Release Notes
    • Astera 8.5 Release Notes
  • Getting Started
    • Astera 8 - Important Considerations
    • Astera 8 - System Requirements
    • Configuring the Server
    • Connecting to a Different Astera Server from the Lean Client
    • Connecting to an Astera Server using Lean Client
    • How to Build a Cluster Database and Create a Repository
    • How to Login from Lean Client
    • Setting up a Server Certificate (.pfx) File in a New Environment
    • Installing Client and Server Applications
    • Licensing Model in Astera 8
    • Migrating from Astera 7.x to Astera 8
    • UI Walkthrough - Astera 8.0
    • User Roles and Access Control
  • Dataflows
    • Sources
      • Data Providers and File Formats Supported in Astera
      • Setting Up Sources
      • COBOL File Source
      • Database Table Source
      • Data Model Query Source
      • Delimited File Source
      • Email Source
      • Excel Workbook Source
      • File Systems Item Source
      • Fixed Length File Source
      • PDF Form Source
      • Report Source
      • SQL Query Source
      • XML/JSON File Source
    • Transformations
      • Introducing Transformations
      • Aggregate Transformation
      • Constant Value Transformation
      • Data Cleanse Transformation
      • Denormalize Transformation
      • Distinct Transformation
      • Database Lookup Transformation
      • Expression Transformation
      • File Lookup Transformation
      • Filter Transformation
      • Join Transformation
      • List Lookup Transformation
      • Merge Transformation
      • Normalize Transformation
      • Passthru Transformation
      • Reconcile Transformation
      • Route Transformation
      • Sequence Generator Transformation
      • Sort Transformation
      • Sources as Transformations
      • Subflow Transformation
      • SQL Statement Lookup Transformation
      • Switch Transformation
      • Tree Join Transformation
      • Tree Transform
      • Union Transformation
    • Destinations
      • Setting Up Destinations
      • Database Table Destination
      • Delimited File Destination
      • Excel Workbook Destination
      • Fixed Length File Destination
      • SQL Statement Destination
      • XML/JSON File Destination
    • Data Logging and Profiling
      • Creating Data Profile
      • Creating Field Profile
      • Data Quality Mode
      • Record Level Log
      • Using Data Quality Rules in Astera
    • Database Write Strategies
      • Database Diff Processor
      • Data Driven Write Strategy
      • Dimension Loader - Database Write
      • Source Diff Processor
    • Text Processors
      • Delimited Parser
      • Delimited Serializer
      • Fixed Length Parser
      • Fixed Length Serializer
      • Language Parser
      • XML JSON Parser
      • XML JSON Serializer
    • Data Warehouse
      • Fact Table Loader
      • Dimension Table Loader
  • WORKFLOWS
    • What Are Workflows?
    • Using the Workflow Designer
    • Creating Workflows in Astera
    • Decision Task
    • EDI Acknowledgement Task
    • File System Task
    • File Transfer Task
    • OR Task
    • Run Dataflow Task
    • Run Program Task
    • Run SQL File Task
    • Run SQL Script Task
    • Run Workflow Task
    • Send Mail Task
    • Workflows with a Dynamic Destination Path
    • Customizing Workflows with Parameters
    • GPG-Integrated File Decryption in Astera
  • Subflows
    • Using Subflows in Astera
  • Functions
    • Introducing Function Transformations
    • Custom Functions
    • Logical
      • Coalesce (Any value1, Any value2)
      • IsNotNull (AnyValue)
      • IsRealNumber (AnyValue)
      • IsValidSqlDate (Date)
      • IsDate (AnyValue)
      • If (Boolean)
      • If (DateTime)
      • If (Double)
      • Exists
      • If (Int64)
      • If (String)
      • IsDate (str, strformat)
      • IsInteger (AnyValue)
      • IsNullOrWhitespace (StringValue)
      • IsNullorEmpty (StringValue)
      • IsNull (AnyValue)
      • IsNumeric (AnyValue)
    • Conversion
      • GetDateComponents (DateWithOffset)
      • ParseDate (Formats, Str)
      • GetDateComponents (Date)
      • HexToInteger (Any Value)
      • ToInteger (Any value)
      • ToDecimal (Any value)
      • ToReal (Any value)
      • ToDate (String dateStr)
      • TryParseDate (String, UnknownDate)
      • ToString (Any value)
      • ToString (DateValue)
      • ToString (Any data, String format)
    • Math
      • Abs (Double)
      • Abs (Decimal)
      • Ceiling (Real)
      • Ceiling(Decimal)
      • Floor (Decimal)
      • Floor (Real)
      • Max (Decimal)
      • Max (Date)
      • Min (Decimal)
      • Min (Date)
      • Max (Real)
      • Max (Integer)
      • Min (Real)
      • Pow (BaseExponent)
      • Min (Integer)
      • RandomReal (Int)
      • Round (Real)
      • Round (Real Integer)
      • Round (Decimal Integer)
      • Round (Decimal)
    • Financial
      • DDB
      • FV
      • IPmt
      • IPmt (FV)
      • Pmt
      • Pmt (FV)
      • PPmt
      • PPmt (FV)
      • PV (FV)
      • Rate
      • Rate (FV)
      • SLN
      • SYD
    • String
      • Center (String)
      • Chr (IntAscii)
      • Asc (String)
      • AddCDATAEnvelope
      • Concatenate (String)
      • ContainsAnyChar (String)
      • Contains (String)
      • Compact (String)
      • Find (Int64)
      • EndsWith (String)
      • FindIntStart (Int32)
      • Extract (String)
      • GetFindCount (Int64)
      • FindLast (Int64)
      • GetDigits (String)
      • GetLineFeed
      • Insert (String)
      • IsAlpha
      • GetToken
      • IndexOf
      • IsBlank
      • IsLower
      • IsUpper
      • IsSubstringOf
      • Length (String)
      • LeftOf (String)
      • Left (String)
      • IsValidName
      • Mid (String)
      • PadLeft
      • Mid (String Chars)
      • LSplit (String)
      • PadRight
      • ReplaceAllSpecialCharsWithSpace
      • RemoveChars (String str, StringCharsToRemove)
      • ReplaceLast
      • RightAlign
      • Reverse
      • Right (String)
      • RSplit (String)
      • SplitStringMultipleRecords
      • SplitStringMultipleRecords (2 Separators)
      • SplitString (3 separators)
      • SplitString
      • SplitStringMultipleRecords (3 Separators)
      • Trim
      • SubString (NoOfChars)
      • StripHtml
      • Trim (Start)
      • TrimExtraMiddleSpace
      • TrimEnd
      • PascalCaseWithSpace (String str)
      • Trim (String str)
      • ToLower(String str)
      • ToProper(String str)
      • ToUpper (String str)
      • Substring (String str, Integer startAt)
      • StartsWith (String str, String value)
      • RemoveAt (String str, Integer startAt, Integer noofChars)
      • Proper (String str)
      • Repeat (String str, Integer count)
      • ReplaceAll (String str, String lookFor, String replaceWith)
      • ReplaceFirst (String str, String lookFor, String replaceWith)
      • RightOf (String str, String lookFor)
      • RemoveChars (String str, String charsToRemove)
      • SplitString (String str, String separator1, String separator2)
    • Date Time
      • AddMinutes (DateTime)
      • AddDays (DateTimeOffset)
      • AddDays (DateTime)
      • AddHours (DateTime)
      • AddSeconds (DateTime)
      • AddMonths (DateTime)
      • AddMonths (DateTimeOffset)
      • AddMinutes (DateTimeOffset)
      • AddSeconds (DateTimeOffset)
      • AddYears (DateTimeOffset)
      • AddYears (DateTime)
      • Age (DateTime)
      • Age (DateTimeOffset)
      • CharToSeconds (Str)
      • DateDifferenceDays (DateTimeOffset)
      • DateDifferenceDays (DateTime)
      • DateDifferenceHours (DateTimeOffset)
      • DateDifferenceHours (DateTime)
      • DateDifferenceMonths (DateTimeOffset)
      • DateDifferenceMonths (DateTime)
      • DatePart (DateTimeOffset)
      • DatePart (DateTime)
      • DateDifferenceYears (DateTimeOffset)
      • DateDifferenceYears (DateTime)
      • Month (DateTime)
      • Month (DateTimeOffset)
      • Now
      • Quarter (DateTime)
      • Quarter (DateTimeOffset)
      • Second (DateTime)
      • Second (DateTimeOffset)
      • SecondsToChar (String)
      • TimeToInteger (DateTime)
      • TimeToInteger (DateTimeOffset)
      • ToDate Date (DateTime)
      • ToDate DateTime (DateTime)
      • ToDateString (DateTime)
      • ToDateTimeOffset-Date (DateTimeOffset)
      • ToDate DateTime (DateTimeOffset)
      • ToDateString (DateTimeOffset)
      • Today
      • ToLocal (DateTime)
      • ToJulianDate (DateTime)
      • ToJulianDayNumber (DateTime)
      • ToTicks (Date dateTime)
      • ToTicks (DateTimeWithOffset dateTime)
      • ToUnixEpoc (Date dateTime)
      • ToUtc (Date dateTime)
      • UnixTimeStampToDateTime (Real unixTimeStamp)
      • UtcNow ()
      • Week (Date dateTime)
      • Week (DateTimeWithOffset dateTime)
      • Year (Date dateTime)
      • Year (DateTimeWithOffset dateTime)
      • DateToJulian (Date dateTime, Integer length)
      • DateTimeOffsetUtcNow ()
      • DateTimeOffsetNow ()
      • Day (DateTimeWithOffset dateTime)
      • Day (Date dateTime)
      • DayOfWeekStr (DateTimeWithOffset dateTime)
      • DayOfWeek (DateTimeWithOffset dateTime)
      • DayOfWeek (Date dateTime)
      • DateToJulian (DateTimeWithOffset dateTime, Integer length)
      • DayOfWeekStr (Date dateTime)
      • FromJulianDate (Real julianDate)
      • DayOfYear (Date dateTime)
      • DaysInMonth(Integer year, Integer month)
      • DayOfYear (DateTimeWithOffset dateTime)
      • FromUnixEpoc
      • FromJulianDayNumber (Integer julianDayNumber)
      • FromTicksUtc(Integer ticks)
      • FromTicksLocal(Integer ticks)
      • Hour (Date dateTime)
      • Hour (DateTimeWithOffset dateTime)
      • Minute (Date dateTime)
      • JulianToDate (String julianDate)
      • Minute (DateTimeWithOffset dateTime)
      • DateToIntegerYYYYMMDD (DateTimeWithOffset dateTime)
      • DateToIntegerYYYYMMDD (Date dateTime)
    • Files
      • AppendTextToFile (String filePath, String text)
      • CopyFile (String sourceFilePath, String destFilePath, Boolean overWrite)
      • CreateDateTime (String filePath)
      • DeleteFile (String filePath)
      • DirectoryExists (String filePath)
      • FileExists (String filePath)
      • FileLength (String filePath)
      • FileLineCount (String filePath)
      • GetDirectory (String filePath)
      • GetEDIFileMetaData (String filePath)
      • GetExcelWorksheets (String excelFilePath)
      • GetFileExtension (String filePath)
      • GetFileInfo (String filePath)
      • GetFileName (String filePath)
      • GetFileNameWithoutExtension (String filePath)
      • LastUpdateDateTime (String filePath)
      • MoveFile (String filePath, String newDirectory)
      • ReadFileBytes (String filePath)
      • ReadFileFirstLine (String filePath)
      • ReadFileText (String filePath)
      • ReadFileText (String filePath, String codePage)
      • WriteBytesToFile (String filePath, ByteArray bytes)
      • WriteTextToFile (String filePath, String text)
    • Date Time With Offset
      • ToDateTimeOffsetFromDateTime (dateTime String)
      • ToUtc (DateTimeWithOffset)
      • ToDateTimeOffsetFromDateTime
      • ToDateTimeOffset (String dateTimeOffsetStr)
      • ToDateTimeFromDateTimeOffset
    • GUID
      • NewGuid
    • Encoding
      • ToBytes
      • FromBytes
      • UrlEncode
      • UrlDecode
    • Regular Expressions
      • ReplaceRegEx
      • ReplaceRegEx (Integer StartAt)
    • TimeSpan
      • Minutes
      • Hours
      • Days
      • Milliseconds
    • Matching
      • Soundex
      • DoubleMetaphone
      • RefinedSoundex
  • Report Model
    • User Guide
      • Report Model Tutorial
    • Report Model Interface
      • Field Properties Panel
      • Region Properties Panel
      • Report Browser
      • Report Options
    • Use Cases
      • Applying Pattern to Line
      • Auto Creating Data Regions and Fields
      • Auto-Parsing
      • Creating Multi-Column Data Regions
      • Floating Patterns and Floating Fields
      • How To Work With PDF Scaling Factor in a Report Model
      • Line Count
      • Pattern Count
      • Pattern is a Regular Expression
    • Exporting Options
      • Exporting a Report Model
      • Exporting Report Model to a Dataflow
    • Miscellaneous
      • Importing Monarch Models
      • Microsoft Word and Rich Text Format Support
      • Working With Problematic PDF Files
  • API Flows
    • API Consumption
      • Consume
        • REST API Browser
        • Making HTTP Requests Through REST API Browser
        • Using REST Client Outside of the Scope of the Project
      • Authorize
        • Authorizing ActiveCampaign API in Astera
        • Authorizing Astera Server APIs
        • Authorizing Avaza APIs in Astera
        • Authorizing Facebook APIs in Astera
        • Authorizing QuickBooks API in Astera
        • Authorizing Square API in Astera
        • Open APIs - Configuration Details
  • Project Management
    • Project Management
      • Astera's Project Explorer
      • Connecting to Source Control
      • Deployment
      • Server Monitoring and Job Management
    • Job Scheduling
      • Scheduling Jobs on the Server
      • Job Monitor
  • Use Cases
    • End-to-End Use Cases
      • Data Integration
        • Using Astera to Create and Orchestrate an ETL Process for Partner Onboarding
      • Data Warehousing
        • Building a Data Warehouse - A Step-By-Step Approach
      • Data Extraction
        • Reusing The Extraction Template for Similar Layout Files
  • Connectors
    • Connecting to Amazon Aurora Database
    • Connecting to Amazon RDS Databases
    • Connecting to Amazon Redshift Database
    • Connecting to Cloud Storage
    • Connecting to Google Cloud SQL in Astera
    • Connecting to MariaDB Database
    • Connecting to Microsoft Azure Databases
    • Connecting to MySQL Database
    • Connecting to Netezza Database
    • Connecting to Oracle Database
    • Connecting to PostgreSQL in Astera
    • Connecting to Salesforce Database
    • Connecting to Salesforce - Legacy Database
    • Connecting to SAP HANA Database
    • Connecting to Snowflake Database
    • Connecting to Vertica Database
    • Setting Up IBM DB2 iSeries Connectivity in Astera
  • Miscellaneous
    • Cloud Deployment
      • Deploying Astera on Amazon Web Services
      • Deploying Astera on Microsoft Azure Cloud
      • Deploying Astera on Oracle Cloud
    • Context Information
    • Pushdown Mode
    • Role Based Access Control in Astera
    • Safe Mode
    • Server Command Line Utility
    • SmartMatch Feature
    • Synonym Dictionary File
    • Updating Your License in Astera
    • Using Dynamic Layout/Template Mapping in Astera
    • Using Output Variables in Astera
    • Using the Data Source Browser in Astera
  • Best Practices
    • Astera Best Practices - Dataflows
    • Overview of Cardinality in Data Modeling
    • Cardinality Errors FAQs
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On this page
  • Use-Case
  • Creating a Subflow
  • Subflow Input and Output
  • Subflow Input
  • Subflow Output
  • Designing a Subflow
  • Using the Subflow Transformation Object in a Dataflow
  1. Subflows

Using Subflows in Astera

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Last updated 9 months ago

The Subflow feature can be seen as a ‘black box’ inside a dataflow. It simplifies and streamlines the dataflow design, increases reusability, and achieves an easier-to-understand view of the dataflow. Unlike dataflows, a subflow cannot run on its own. You must call a subflow in a dataflow for it to be executed.

A subflow can be nested, meaning that you can call a Subflow transformation object in another subflow.

Over time, if the logic inside your subflow changes, you can modify the subflow, and use it in the same dataflow as before. This saves the user from making repeated changes in the dataflow when the subflow is being called multiple times. This will be clearer when we study the example use case given below.

Use-Case

In this example, we have datasets of Student Allowance for three different classes: Primary, Secondary, and High School Students, stored in three separate Excel files. For each student in a particular class, we have four allowance categories: Lunch, Books, Uniform, and Stationery.

Here is a preview of the data for Primary School Students:

First, we want to refine our data by removing duplicate records. Next, we want to find the total amount a student gets (the sum of all 4 categories) and the following statistics for each class. Finally, we will save the outputs in separate Excel destinations:

  • Average total allowance

  • Minimum total allowance

  • Maximum total allowance

Here is the desired sample output summary for Primary School Students:

The logic implemented in the dataflow to get the output shown above is as follows:

Observe that performing the same process three times for each class of students would be repetitive. Therefore, we will use the Subflow object to create the repeating logic.

Creating a Subflow

  1. Open a new Subflow. To open a new Subflow, go to File > New > Subflow or press the shortcut keys Ctrl+Shift+S.

Alternatively, you can expand the dropdown in the main toolbar and select Subflow as shown below.

Subflow Input and Output

The Subflow Input object makes it possible to feed data into the subflow from an upstream object in the dataflow that calls the subflow. The Subflow Output object sends data to the downstream dataflow object connected to the subflow.

You can find the Subflow Input and Subflow Output objects in the Subflow section of the Toolbox.

Note: The Subflow section will only appear in the Toolbox if a Subflow file is open.

Drag and drop these items onto the subflow designer to use them.

Subflow Input

The Subflow Input object is a connector controlling the input layout of your subflow. Any data fed into the subflow will pass through the Subflow Input when the subflow is called by a dataflow or another subflow.

  1. Right-click on the Subflow Input object and select Properties.

  1. Add appropriate data fields, along with their data types, in the Layout Builder, and click OK.

  1. Your Subflow Input object is now configured and ready for use.

Subflow Output

The Subflow Output object is a connector controlling the output layout of your subflow. Any data that leaves the subflow will pass through the Subflow Output when the subflow is called by a dataflow or another subflow.

  1. Like the previous step, right-click on the Subflow Output object and select Properties.

  1. Add appropriate data fields, along with their data types, and click OK.

  1. Your Subflow Input and Subflow Output objects are now configured.

Designing a Subflow

Add required objects between your Subflow Input and Subflow Output objects and map the respective data fields.

In this case, we have added the following transformations:

Once done, save your subflow in the relevant directory with an appropriate name. Here, we will name it, SampleSubflow.Sf.

Using the Subflow Transformation Object in a Dataflow

  1. Then, drag and drop the Subflow object from the Transformation section of the Toolbox onto the designer.

  1. Right-click on the Subflow object and select Properties.

  1. Copy and paste the Path of the directory where the SampleSubflow.Sf is saved.

Alternatively, you can click on the folder icon on the right of the textbox to locate the file, SampleSubflow.Sf, in your local directory. Click Open.

Click OK in the Properties window.

  1. Your Subflow transformation object is now configured and ready for use. You can now map appropriate data fields from and to the Excel Source and Excel Destination respectively.

  1. Right-click on the ExcelDest object and select Preview Output. It should display the Average, Maximum, and Minimum total allowance for Primary School Students.

  1. Repeat the same steps given above for the other two datasets containing information on student allowance for Secondary School Students and High School Students.

This concludes our discussion on the functionality of the Subflow Input, Subflow Output, and Subflow transformation objects in Astera Data Stack.

In our example, we need our subflow to take the student allowance details as the input using the Subflow Input object. We can also use any other source object, such as an .

: To remove all duplicate records and keep only records with distinct IDs.

: To find the Total for each student by summing the amount in all four columns (Col1 + Col2 + Col3 + Col4).

: To find the Average, Min, and Max total allowance of each student.

Make a new dataflow, import data from the respective , and create data fields in the respective . Your designer will look like this:

Excel Workbook Source
Distinct
Expression
Aggregate
Excel Workbook Source
Excel Workbook Destination