Overview

An UNPIVOT operation converts columns into rows. You can use this Snap to add the UNPIVOT operation to an incoming SQL query for Snowflake, Redshift, Azure Synapse, Databricks Lakehouse Platform (DLP), and BigQuery databases. Azure Synapse and Databricks Lakehouse Platform (DLP) do not support Pivot/Unpivot operations natively, but the Snap supports them internally through a series of rewrite mechanisms.

Prerequisites

None.

Limitation

Known Issues

Snap Input and Output

Input/Output	Type of View	Number of Views	Examples of Upstream and Downstream Snaps	Description

Input/Output	Type of View	Number of Views	Examples of Upstream and Downstream Snaps	Description
Input	Document	Min: 1 Max: 1	ELT Select ELT Transform	The SQL query in which to add the UNPIVOT function. Typically, it is a SELECT query reading the source table.
Output	Document	Min: Max:	ELT Insert-Select ELT Filter	The incoming SQL query with the UNPIVOT function.

Snap Settings

SQL Functions and Expressions for ELT

You can use the SQL Expressions and Functions supported for ELT to define your Snap or Account settings with the Expression symbol = enabled, where available. This list is common to all target CDWs supported. You can also use other expressions/functions that your target CDW supports.

Parameter Name	Data Type	Description	Default Value	Example

Parameter Name	Data Type	Description	Default Value	Example
Label	String		ELT Unpivot	Sales Data
Get preview data	Checkbox		Not selected	Selected
Value Column	String	Required. Enter the name for the generated column that shows the values corresponding to the columns specified in the Column List field set.	N/A	Sales
Name Column	String	Required. Enter the name for the generated column that shows the names corresponding to the columns specified in the Column List field set.	N/A	Month
Column List	Required. Use this field set to specify the columns in the source table to convert into rows. You must add each column in a separate row. Click to add a row. This field set contains the Column field.
Column	String	Required. Enter the names of the columns to convert into rows.	N/A	Jan Feb Mar

Troubleshooting

None.

Example

Consolidating Quarterly Sales of an Employee

We want to consolidate the quarterly sales of an employee. The source table that captures the sales data is organized by month, meaning that the employee's sales are recorded in a single row, where the months are organized as columns. We need to first convert the column data into row data and then write this modified data into another table. This Pipeline demonstrates how we can use the ELT Unpivot Snap to accomplish this task.

First, we build a SELECT query to read the target table. To do so, we use the ELT Select Snap. Sales data is maintained in the table SALES_BY_3_MONTHS. We want to retrieve the sales data for the employee with ID 1. We configure the ELT Select Snap to read this table. Additionally, we also configure the Snap to show a preview of the SELECT query's execution:

A preview of the output from the ELT Select Snap is shown below:

As seen from the above screenshot, the sales data is organized by months. Each month is a separate column. Therefore, we use the ELT Unpivot Snap and configure it to change the columns into rows as shown below:

A preview of the output from the ELT Unpivot Snap is shown below:

Based on the ELT Unpivot Snap's configuration, the month-based columns are turned into rows under a new column MONTH. Similarly, the sales amounts for each of these months are placed under the AMOUNT column.

We use an ELT Insert-Select Snap to write the above output into another table as shown below:

We can now use the data in the new table SALES_BY_3_MONTHS_UNPIVOT_OUT to conduct further analysis and processing.

Download this Pipeline.

Downloads

Important Steps to Successfully Reuse Pipelines

Download and import the Pipeline into SnapLogic.
Configure Snap accounts as applicable.
Provide Pipeline parameters as applicable.

ELT Unpivot