Astera Data Stack
Version 6
Version 6
  • Welcome to Astera Data Stack Documentation
  • Release Notes
    • Upgrading from Astera 5.1 to 6.0
  • Getting Started
    • Introduction to Astera 6 Webinar Video
  • Dataflows
    • Introducing Dataflows
    • Dataflow Examples
    • Parameterizing Dataflows
    • Sources
      • Setting Up Sources
      • ADO.Net Metadata Collections Source
      • COBOL File Source
      • Data Model Source
      • Database Table Source
      • Delimited File Source
      • Excel File Source
      • File System Entries Source
      • Fixed Length File Source
      • SQL Query Source
      • XML/JSON File Source
    • Transformations
      • Introducing Transformations
      • Aggregate Transformation
      • Apply To All Transformation
      • Constant Value Transformation
      • Data Quality Rules Transformation
      • Denormalize Transformation
      • Distinct Transformation
      • Expression Transformation
      • Filter Transformation
      • Join Transformation
      • Merge Transformation
      • Normalize Transformation
      • Passthru Transformation
      • REST Client
      • Route Transformation
      • Sequence Generator
      • Sort Transformation
      • Subflow Transformation
      • Tree Join Transformation
      • Union Transformation
      • Web Service Transformation
    • Destinations
      • Setting Up Destinations
      • Database Table Destination
      • Delimited File Destination
      • Excel File Destination
      • Fixed Length File Destination
      • SQL Statement Destination
      • XML File Destination
    • Maps
      • Linking and Mapping Objects
      • Creating Constant Value Maps
      • Creating Database Lookup Maps
      • Creating Direct Maps
      • Creating Expression Maps
      • Creating Function Maps
      • Creating List Lookup Maps
      • Creating SQL Statement Lookup Maps
    • Data Logging and Profiling
      • Creating Data Profiles
      • Creating Field Profiles
      • Using Data Quality Mode
      • Using Data Quality Rules
      • Using Record Level Log
    • Database Write Strategies
      • Database Write Strategies
  • Workflows
    • Adding Workflow Tasks
    • Creating Workflows
    • Customizing Workflows With Parameters
    • Using Workflow Designer
  • Subflows
    • Using Subflows in Astera
  • Report Model
    • Report Model Tutorial
    • Applying an Existing Model to a New Report
    • Using Report Models to Extract Business Information from Printed Documents
  • Functions
    • Introducing Function Transformations
    • Functions Glossary
    • 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
  • Integration Server
    • Job Scheduling
      • Scheduling and Running Jobs on a Server
  • Miscellaneous
    • Astera API User Guide
    • Astera Best Practices Dataflows
    • Astera Options
    • Astera Webinar Series
    • MySQL date/time conversion error
    • Report Model Monthly Online Training
    • Server Command Line Utility
    • Shared Actions
    • Shared Connections
    • Working with Data Formats
    • Using the Data Source Browser
    • Using the Query Editor
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On this page
  • Aggregates
  • Usage
  1. Dataflows
  2. Maps

Creating Expression Maps

PreviousCreating Direct MapsNextCreating Function Maps

Last updated 9 months ago

Expression map defines an expression transforming the incoming value (or values) according to some logic, called expression. For example, you may use expressions like the following to get the expression result based on the input data:

Input.Amortization + 120

AddDays(Input.AccountFundingDate, 30)

Floor(Input.NoteRate)

If (Input.IsFunded = “True”, 1, 0)

Month(Input.DueDate)

Some expressions do not depend on any user-provided input data, for example Now().

All expressions return an output value of an appropriate data type. The output value is available under the Output node on the object box.

To add an Expression map, drag the Expression object from the Maps group in the Flow toolbox and drop it on the dataflow.

An example of what an Expression Map object might look like is shown below:

To configure the properties of an Expression object after it was added to the dataflow, right-click on it and select Properties from the context menu. The following properties are available:

  • Meta Object Builder screen: Meta Object Builder screen allows you to add or remove fields in the field layout, as well as select their data type. The fields added in Meta Object Builder will show in the Input node of the Expression object. The Input node can be connected to upstream dataflow objects in order to supply the field values used by the expression.

  • Expression Map Properties screen provides the interface to help you create your expression.

  • General Options screen: This screen shares the options common to most objects on the dataflow.

Aggregates

Aggregate functions are available in many places throughout Astera, including Expression Maps, Data Quality Rules and Record Filter Expressions. Using aggregate functions, for instance, you can calculate the maximum loan amount among all records in a given collection.

To make sure your aggregate functions are properly formed, you need to specify paths relative to the collection (as opposed to root based paths). For instance, if you have a structure like this:

Customer(Id, Name)

​ SalesOrder(OrderId, Amount)

​ OrderDetail(Quantity, Price, Total)

your aggregate functions would look like this:

Customer.SalesOrder.Sum(Amount)

Customer.SalesOrder.OrderDetail(Quantity), and not Customer.SalesOrder.OrderDetail(Customer.SalesOrder.OrderDetail.Quantity)

Usage

A fragment of a dataflow with Expression objects is shown below: