Astera Data Stack
Version 9
Version 9
  • Welcome to Astera Data Stack Documentation
  • Release Notes
    • Astera 9.0 - Release Notes
  • Setting Up
    • System Requirements
    • Product Architecture
    • Installing Client and Server Applications
    • Connecting to a Astera Server using Lean Client
    • How to Connect to a Different Astera Server from the Lean Client
    • How to Set up a Server Certificate (.pfx) File in a New Environment
    • How to Build a Cluster Database and Create a Repository
    • How to Login from Lean Client
    • Licensing Model in Astera 9
    • User Roles and Access Control
    • Offline Activation of Astera Data Stack
  • Dataflows
    • Sources
      • Data Providers and File Formats Supported in Astera Data Stack
      • Setting Up Sources
      • Excel Workbook Source
      • COBOL File Source
      • Database Table Source
      • Delimited File Source
      • File System Items Source
      • Fixed Length File Source
      • Email Source
      • Report Source
      • SQL Query Source
      • XML/JSON File Source
      • PDF Form Source
    • Transformations
      • Introducing Transformations
      • Aggregate Transformation
      • Constant Value Transformation
      • Denormalize Transformation
      • Distinct Transformation
      • Expression Transformation
      • Filter Transformation
      • Join Transformation
      • List Lookup Transformation
      • Merge Transformation
      • Normalize Transformation
      • Passthru Transformation
      • Reconcile Transformation
      • Route Transformation
      • Sequence Generator
      • Sort Transformation
      • Sources as Transformations
      • Subflow Transformation
      • Switch Transformation
      • Tree Join Transformation
      • Tree Transform
      • Union Transformation
      • Data Cleanse Transformation
      • File Lookup Transformation
      • SQL Statement Lookup
      • Database Lookup
    • Destinations
      • Setting Up Destinations
      • Database Table Destination
      • Delimited File Destination
      • Excel Workbook Destination
      • Fixed Length File Destination
      • SQL Statement Destination
      • XML File Destination
    • Data Logging and Profiling
      • Creating Data Profile
      • Creating Field Profile
      • Data Quality Mode
      • Using Data Quality Rules in Astera
      • Record Level Log
    • Database Write Strategies
      • Data Driven
      • Source Diff Processor
      • Database Diff Processor
      • Dimension Loader - Database Write
    • Text Processors
      • Delimited Parser
      • Delimited Serializer
      • Language Parser
      • Fixed Length Parser
      • Fixed Length Serializer
      • XML/JSON Parser
      • XML JSON Serializer
    • Visualizations
      • Basic Plots
      • Distribution Plots
  • Workflows
    • What are Workflows?
    • Creating Workflows in Astera
    • Decision Task
    • EDI Acknowledgment 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
  • DATA MODEL
    • Creating a Data Warehousing Project
    • Data Models
      • Introducing Data Models
      • Opening a New Data Model
      • Data Modeler - UI Walkthrough
      • Reverse Engineering an Existing Database
      • Creating a Data Model from Scratch
      • General Entity Properties
      • Creating and Editing Relationships
      • Forward Engineering
      • Verifying a Data Model
    • Dimensional Modelling
      • Introducing Dimensional Models
      • Converting a Data Model to a Dimensional Model
      • Fact Entities
      • Dimension Entities
      • Date and Time Dimension
      • Verifying a Dimensional Model
    • Documentation
      • Generating Technical and Business Documentation for Data Models
      • Lineage and Impact Analysis
    • Deployment and Usage
      • Deploying a Data Model
      • Validate Metadata and Data Integrity
      • Using Astera Data Models in ETL Pipelines
      • Connecting an Astera Data Model to a Third Party Visualization Tool
  • 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
      • Report Options
      • Report Browser
      • Data Regions in Report Models
      • Region Properties Panel
      • Pattern Properties
      • Field Properties Panel
    • Use Cases
      • Applying Pattern to Line
      • Auto Creating Data Regions and Fields
      • Auto Parsing
      • Connecting to Cloud Storage
      • Creating Multi Column Data Regions
      • Defining Region End Type as Specific Text and Regular Expression
      • Defining the Start Position of Data Fields
      • 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
      • Using Comma Separated Values to Define Start Position
    • Auto Generate Layout (Beta)
      • Setting Up AGL in Astera
      • UI Walkthrough Auto Generation of Layout, Fields and Table
      • Using Auto Generation Layout, Auto Create Fields, and Auto Create Table (Beta)
    • 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 Connection
        • Making API Calls with the REST Client Object in Astera
        • REST API Browser
        • Method Operations
        • Pagination
      • Authorize
        • Open APIs - Configuration Details
        • Authorizing Facebook APIs in Astera
        • Authorizing Astera's Server APIs
        • Authorizing Avaza APIs in Astera
        • Authorizing Square API in Astera
        • Authorizing ActiveCampaign API in Astera
        • Authorizing QuickBooks’ API in Astera
        • Accessing Astera's Server APIs Through a Third Party Tool
        • Astera's Server API Documentation
  • Project Management
    • Project Management
      • Deployment
      • Server Monitoring and Job Management
      • Connecting to Source Control
      • Astera Project and Project Explorer
    • Job Scheduling
      • Scheduling Jobs on the Server
      • Job Monitor
  • Use Cases
    • End-to-End Use Cases
      • Data Integration
        • Using Astera Data Stack 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
    • Setting Up IBM DB2/iSeries Connectivity in Astera
    • Connecting to SAP HANA Database
    • Connecting to MariaDB Database
    • Connecting to Salesforce Database
    • Connecting to Salesforce - Legacy Database
    • Connecting to Vertica Database
    • Connecting to Snowflake Database
    • Connecting to Amazon Redshift Database
    • Connecting to Amazon Aurora Database
    • Connecting to Google Cloud SQL in Astera
    • Connecting to MySQL Database
    • Connecting to PostgreSQL in Astera
    • Connecting to Netezza Database
    • Connecting to Oracle Database
    • Connecting to Microsoft Azure Databases
    • Connecting to Amazon RDS Databases
  • Miscellaneous
    • Using Dynamic Layout Template Mapping in Astera
    • Synonym Dictionary File
    • SmartMatch Feature
    • Role Based Access Control in Astera
    • Updating Your License in Astera
    • Using Output Variables in Astera
    • Connection Vault
    • Safe Mode
    • Using the Data Source Browser in Astera
    • Pushdown Mode
    • Cloud Deployment
      • Deploying Astera on Microsoft Azure Cloud
      • Deploying Astera on Oracle Cloud
      • Deploying Astera on Amazon Web Services
    • Context Information
  • Best Practices
    • Overview of Cardinality in Data Modeling
    • Cardinality Errors FAQs
    • Astera Best Practices - Dataflows
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  1. Subflows

Using Subflows in Astera

PreviousGPG-Integrated File Decryption in AsteraNextCreating a Data Warehousing Project

Last updated 11 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 _ID_s.

: 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