FunSQL: a library for compositional construction... | Clark C. Evans, Kyrylo Simonov | JuliaCon 2021

This talk was presented as part of JuliaCon 2021.

Abstract:
Julia programmers sometimes need to interrogate data with the Structured Query Language (SQL). But SQL is notoriously hard to write in a modular fashion. There is no way to reuse SQL query fragments among different queries.

FunSQL exposes the full expressive power of SQL with compositional semantics. FunSQL allows you to build queries incrementally from small independent fragments. This approach is particularly useful for building applications that programmatically construct SQL queries.

Contents
00:00 Welcome!
00:10 FunSQL.jl: Who needs it?
00:39 Problem: query on user input
01:47 Query algebra
02:11 Scheme of a database
02:56 Describing scheme of a database in FunSQL.jl
03:17 Cratering query
04:12 Bound and unbound references
04:57 Generating SQL function
05:21 JOIN clause
06:36 Example: using JOIN to create a query
07:05 SQL and FunSQL.jl grammar can differ
08:31 (query algebra) How FunSQL.jl query constructor works
09:47 FunSQL.jl special set of constructors
11:03 Inspecting query object
11:58 Query parameters
12:29 Correlated queries
13:39 FunSQL.jl syntax for correlated queries
14:42 Aggregate functions
17:17 Window functions
18:12 In FunSQL.jl aggregate and window functions use the same notation, but different constructors
19:16 Example: merging overlapping visits
20:44 Conclusions
20:58 Example: solving the problem from the beginning of the talk
21:47 Current state of FunSQL.jl and plans for the future

[rolandschatzle]

That’s an interesting package and a good way to create reusable modules of SQL code. The presentation explains the objectives and the concepts very well; it was a pleasure to view 😊👍

[chidemenot]

Good work, hope to see more improvements to come ...My Best Wishes