Join files (3) block

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This block will be deprecated in a future release.

The three_join block merges three source files into a single output file based on specified join conditions and matching headers. It acts as a transformation block in a Connect+ dataflow, enabling you to combine data from three separate files using SQL-style join operations before passing the merged output to downstream blocks.

When to use this block

Use this block when your dataflow needs to combine data from three separate files — for example, merging bill-level, line-level, and payment mode files before ingestion.

Prerequisites

Before configuring this block, make sure you have:

Three source files with a common column to join on
Regex patterns that uniquely identify each file

Configuration fields

Field name	Required	Description
Block name	No	A name for the block instance. For example, `Three_Join_Block`.
Files 1-2 Join Type	Yes	The type of SQL join used to merge File 1 and File 2. Select from the dropdown. Default value: `LEFT_OUTER_JOIN`.
Files 1-3 Join Type	Yes	The type of SQL join used to merge the result of Files 1-2 with File 3. Select from the dropdown. Default value: `LEFT_OUTER_JOIN`.
All Files Delimiter	Yes	The delimiter used to separate fields in the source files. For example, `,`.
File 1 Regex	Yes	The filename pattern used to identify File 1. For example, `BILL_LEVEL.*.csv`.
File 1 Headers	Yes	The column header name in File 1 used for the join comparison. To match on multiple headers, enter the header names separated by a comma. For example, `BillNumber`.
File 2 Regex	Yes	The filename pattern used to identify File 2. For example, `LINE_LEVEL.*.csv`.
File 2 Headers	Yes	The column header name in File 2 used for the join comparison. To match on multiple headers, enter the header names separated by a comma. For example, `BillNumber`.
File 3 Regex	Yes	The filename pattern used to identify File 3. For example, `PAYMENT_MODE.*.csv`.
File 3 Headers	Yes	The column header name in File 3 used for the join comparison. To match on multiple headers, enter the header names separated by a comma. For example, `BillNumber`.
Output Filename	Yes	The name of the merged output file. For example, `merged_output.csv`.
File Join Use Case	No	The use case for the file join. Select from the dropdown. Default value: `NONE`.
File One Mention Header names (for use in mapping and expressions)	No	The column header names for File 1, separated by commas. Required if File 1 is headerless. For example, `BillNumber,Amount,Date`.
File One is Headerless	No	Indicates whether File 1 does not contain column headers. Select `true` or `false` from the dropdown. Default value: `false`.
File Two Mention Header names (for use in mapping and expressions)	No	The column header names for File 2, separated by commas. Required if File 2 is headerless. For example, `BillNumber,ItemCode,Quantity`.
File two is Headerless	No	Indicates whether File 2 does not contain column headers. Select `true` or `false` from the dropdown. Default value: `false`.
File three is Headerless	No	Indicates whether File 3 does not contain column headers. Select `true` or `false` from the dropdown. Default value: `false`.
File Three Mention Header names (for use in mapping and expressions)	No	The column header names for File 3, separated by commas. Required if File 3 is headerless. For example, `BillNumber,PaymentMode,Amount`.
Merge based on common Name	No	Determines whether files are identified and merged based on a common name pattern. Select `true` or `false` from the dropdown. Default value: `false`.
Merge based on common Name Template File One	No	The filename template for File 1 using the `<common>` tag to identify the common part of the filename. For example, `TktDocument_<common>.dat`.
Merge based on common Name Template File Two	No	The filename template for File 2 using the `<common>` tag to identify the common part of the filename. For example, `TktDocument_<common>.dat`.
Merge based on common Name Template File Three	No	The filename template for File 3 using the `<common>` tag to identify the common part of the filename. For example, `TktDocument_<common>.dat`.
Use Alphabetical Sort	No	Determines whether files are sorted in alphanumerical order before merging. Select `true` or `false` from the dropdown. Default value: `false`.