12.16. Parameters in Dynamic SQL for BigQuery

Using Parameters with BigQuery

In this lesson, we'll explore using parameters in dynamic SQL queries for BigQuery, and how they can be utilized in Looker Studio to create interactive visualizations. We'll also discuss a practical example of using these parameters to help businesses explore potential locations for their stores.

Learning Objectives

Understand the use of parameters in dynamic SQL queries for BigQuery.
Learn how to incorporate parameters in Looker Studio visualizations.
Apply the concept of dynamic queries and parameters in a real-life business scenario.

Main Concepts and Topics

Dynamic queries: Custom SQL queries that can involve joining multiple tables, filtering data, and more.
Parameters: User-defined values that can be incorporated into dynamic queries to generate custom results.
BigQuery data source: A Google data warehouse that can be connected to Looker Studio.
Geographic functions in SQL: Functions that allow calculating distances and spatial relationships between geographic coordinates.

Dynamic Queries and Parameters

When using a BigQuery data source, you can connect to any table in your dataset or write a custom query against your whole project. This custom query may involve joining multiple tables, filtering data, and more. In these dynamic queries, we can define parameters and obtain their values from the user.

These user inputs dynamically change the values in the SQL statement, such as the latitude and longitude in our example. The query then runs against the BigQuery project and extracts the resulting data into Looker Studio.

Real-Life Example: Exploring Store Locations

Imagine a business wants to open a new store and needs information about the population surrounding a specific location.

First, we obtain the latitude and longitude of the desired location using an external mapping tool, such as Google Maps. In this example, we have the latitude of 41 and the longitude of 73. The client is interested in analyzing the population within a 5-mile radius of this point.

These three values (latitude, longitude, and distance) will be passed to the custom query, which will then calculate the distance of each record to the given point using geographic functions in SQL.

Upon completion, Looker Studio will display the results, such as the number of people living within the 5-mile radius of the chosen location.

Without dynamic queries, creating such an interactive interface would not be possible. Parameters enable users to explore data and gain insights on-the-fly, making them a powerful tool in Looker Studio.