Learn how to access data in maps using Presto.
- [Instructor] Another type of complex data…that you may run into are maps.…And maps and arrays can be used together.…So let's take a look at how to…work with those in Presto here.…I'm going to log into Presto.…And from here I want to create a map of arrays,…if that makes sense.…So select map, array a and b, array apple banana.…And you can see what it did.…It essentially mapped these two things together.…It created a map where you have keys and values…which is what maps are based on.…
So I combined multiple arrays using that map function.…Now I can create multiple maps…using the with function as well.…That would look similar to what we have above…but I'm also going to use something called mapconcat…which combines the arrays.…So first I'll start with my with function.…With maps as select map array…a and b then array apple and banana.…This is m1 so my first map.…And map array c and d and array coconut and date as m2.…
So I have my maps and what I want to do now is combine them.…So I'll use select map_concatm1 and m2 from maps.…
Data science expert Ben Sullins helps you get up to speed with Presto, and leverage it to accomplish a wide-range of data science and analytics tasks. He uses different interfaces with Presto—such as R and Tableau—and digs into the expressive SQL language that Presto offers for your analysis. At the end of this course, you'll know the key concepts of Presto and how to use them to take full advantage of your modern big data system.
- What does Presto do?
- Running Presto
- Connecting from Tableau and R
- Connecting to Hive, MySQL, and the local system
- Retrieving data
- Combining data sources
- Basic SQL functions
- Advanced SQL functions
- Migrating from Hive
Skill Level Intermediate
SQL: Data Reporting and Analysiswith Emma Saunders2h 16m Intermediate
Advanced SQL for Data Scientistswith Dan Sullivan1h 24m Advanced
1. Introducing Presto
2. Running Presto
4. SQL Syntax
5. Basic SQL functions
6. Advanced SQL Functions
7. Migrating from Hive
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