Tableau Funtion: FIRST( )

Tableau Function: FIRST()

Category: Table Calculation Functions

Purpose

The FIRST() function in Tableau is a table calculation that returns the relative position of the first row (or mark) in a partition. It is primarily used to determine ordering and positional logic within a defined window of data.

In simple terms, FIRST() tells you how far the current row is from the first row in the partition.

Type of Calculations

• Table calculations

• Index-based positional calculations

• Relative row positioning

• Order-dependent calculations

Unlike row-level or aggregate functions, FIRST() operates after aggregation, based on how data is displayed in the view.

Practical Use Cases

• Identifying the first record in a sorted list

• Creating rank-based filters

• Calculating running comparisons against the first value

• Building custom index or offset calculations

• Highlighting or labeling the starting point of a partition

How It Works?

Logical Principle

FIRST() calculates the offset distance from the first row in a partition:

Because Tableau counts forward rows as negative offsets:

• The first row is always 0

• Every row after moves backward numerically

Partition Dependency

The result depends on:

• Partitioning (Compute Using)

• Sorting order

• Table calculation direction (Table Down, Pane Across, etc.)

What Does It Return?

• • Data Type: Integer

  • Meaning:

    • Returns 0 for the first row in the partition

    • Returns negative integers (-1, -2, -3, …) for subsequent rows

  Example Output

  Row Position	FIRST()
  1st	0
  2nd	-1
  3rd	-2

When Should We Use It?

Use FIRST() when you need to:

• Identify or isolate the first value in a sorted dataset

• Compare values relative to the starting point

• Create custom filters (e.g., show first N rows)

• Build offset-based metrics

• Control row-aware logic in dashboards

Basic Usage

Identify the first row only

• Returns TRUE only for the first row
• Useful for conditional formatting or labels

Column Usage

Create a calculated field to label the first record

• Labels the first mark in each partition
• Common in ranked or sorted views

Advanced Usage

Compare current value to the first value

• Calculates the difference between each row’s sales and the first row
• Common in trend and variance analysis

Tips and Tricks

• Always check the table calculation direction

• Sorting directly affects FIRST() results

• Use Compute Using carefully to control partitions

• FIRST() does not work without a defined view

• Avoid using it in row-level logic

Related Functions You Might Need

Functions commonly used with or as alternatives to FIRST():

• LAST()

• INDEX()

• LOOKUP()

• RANK()

• RUNNING_SUM()

• WINDOW_MIN()

We’ve got plenty of resources to help you master Tableau functions. For more details, check out the official Tableau documentation. Or, if you’re ready for more practice, let’s dive into related functions and build your Tableau skills further!

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