Generating Tally Tables With Snowflake DB

Kevin Feasel

2018-12-27

Syntax

Koen Verbeeck shows us how to use the GENERATOR function to build a tally table in Snowflake:

I’m starting a little series on some of the nice features/capabilities in Snowflake (the cloud data warehouse). In each part, I’ll highlight something that I think it’s interesting enough to share. It might be some SQL function that I’d really like to be in SQL Server, it might be something else.
In the first part: the GENERATOR function. In short, it lets you generate a virtual table with a specified number of rows, or in database lingo: a tally table (or numbers table). A tally table can help you solve a lot of problems in SQL, but the TL;DR version is that it replaces loops/cursors most of the time and allows you to tackle the issue in a true set-based manner.

Naturally, as I read the article, I got the Bad Religion song stuck in my head. That’s an occupational hazard, I suppose.

Related Posts

Making Dynamic SQL Safe

Erik Darling explains patiently that if you use sp_executesql wrong, you don’t get the benefits of using it right: The gripes I hear about fully fixing dynamic SQL are: – The syntax is hard to remember (setting up and calling parameters)– It might lead to parameter sniffing issues I can sympathize with both. Trading one […]

Read More

CAST and CONVERT Make Expressions Nullable

Daniel Hutmacher points out a side effect of using CAST() and CONVERT(): Suppose we want to set up a view in the new solution that mirrors the names and definitions of the old table, so the legacy integration can use that view going forward: CREATE OR ALTER VIEW new.the_table_like_beforeASSELECT CAST(id AS varchar(32)) AS id, CAST([row] […]

Read More

Categories

December 2018
MTWTFSS
« Nov Jan »
 12
3456789
10111213141516
17181920212223
24252627282930
31