Unpivoting Tables in BigQuery
Restructuring a table to transform rows into columns is a common data manipulation task. In BigQuery, this process is known as unpivoting.
Problem Statement:
Suppose you have a table with data organized in a format similar to the following:
However, your desired output table should be structured like this:
Solution:
To achieve this transformation, you can utilize the UNPIVOT operator in BigQuery. This operator rotates rows into columns, allowing you to reshape your table as required.
Updated Solution (2021):
BigQuery has introduced a dedicated UNPIVOT operator to simplify this process. Using UNPIVOT can be represented as follows:
SELECT product, sales, quarter FROM ( SELECT product, UNNEST([Q1, Q2, Q3, Q4]) AS sales, UNNEST(["Q1", "Q2", "Q3", "Q4"]) AS quarter FROM UNNEST(sales_table) AS sales_table )
This query unpivots the columns Q1, Q2, Q3, Q4 into new columns sales and quarter. The UNNEST operator is used to extract the values from the nested array field sales_table.
The above is the detailed content of How Can I Unpivot Tables in BigQuery to Transform Rows into Columns?. For more information, please follow other related articles on the PHP Chinese website!

The article discusses using MySQL's ALTER TABLE statement to modify tables, including adding/dropping columns, renaming tables/columns, and changing column data types.

Article discusses configuring SSL/TLS encryption for MySQL, including certificate generation and verification. Main issue is using self-signed certificates' security implications.[Character count: 159]

Article discusses strategies for handling large datasets in MySQL, including partitioning, sharding, indexing, and query optimization.

Article discusses popular MySQL GUI tools like MySQL Workbench and phpMyAdmin, comparing their features and suitability for beginners and advanced users.[159 characters]

The article discusses dropping tables in MySQL using the DROP TABLE statement, emphasizing precautions and risks. It highlights that the action is irreversible without backups, detailing recovery methods and potential production environment hazards.

Article discusses using foreign keys to represent relationships in databases, focusing on best practices, data integrity, and common pitfalls to avoid.

The article discusses creating indexes on JSON columns in various databases like PostgreSQL, MySQL, and MongoDB to enhance query performance. It explains the syntax and benefits of indexing specific JSON paths, and lists supported database systems.

Article discusses securing MySQL against SQL injection and brute-force attacks using prepared statements, input validation, and strong password policies.(159 characters)


Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

AI Hentai Generator
Generate AI Hentai for free.

Hot Article

Hot Tools

SublimeText3 Linux new version
SublimeText3 Linux latest version

PhpStorm Mac version
The latest (2018.2.1) professional PHP integrated development tool

Atom editor mac version download
The most popular open source editor

SAP NetWeaver Server Adapter for Eclipse
Integrate Eclipse with SAP NetWeaver application server.

Zend Studio 13.0.1
Powerful PHP integrated development environment