Awesome SQL alternatives

Relational data

SQL transpilers

• PRQL – simpler and more powerful SQL
• Logica – logic programming language (BigQuery, SQLite, PostgreSQL)
• Cytosm – Cypher to SQL
• HTSQL – XPath-like navigational query language for relational databases and web service gateways (PostgreSQL, MySQL, SQLite, Oracle, Microsoft SQL Server)

Other

• Malloy – an experimental language for describing data relationships and transformations, akin to a SQL extension (BigQuery)
• Flux – functional data scripting language (InfluxDB, MySQL, PostgreSQL, CSV)

Language or platform-specific

• FunSQL.jl – library for compositional construction of SQL queries (Julia)
• TreSQL – query language built on SQL that selects data into hierarchical JSON objects (JDBC)
• Kusto Query Language – requests are stated in plain text using a data-flow model that is easy to read, author, and automate (Azure)
• Cloudwatch Logs Insight query language – (Cloudwatch)
• dplyr – grammar of data manipulation, providing a consistent set of verbs (R)
• SQL Frames – low code data management framework that can be directly embedded in the browser to provide rich data visualization and UX (web)

Custom databases

• Rel – an expressive, declarative, and relational language designed for modeling domain knowledge (RelationalAI)
• openCypher – SQL and Cypher queries can be integrated into a single query (AgensGraph, built on PostgreSQL)
• EdgeQL

Poly-store

Query languages which operate on both relational and non-relational data

• PartiQL – treats nested data as first class citizens and composes seamlessly with SQL, enabling intuitive filtering, joining and aggregation on the combination of structured, semistructured and nested datasets (AWS various, others)
• Optic API – makes it possible to perform relational operations on indexed values and documents (Marklogic)

Relational Algebra

• Morel – Standard ML interpreter with relational extensions
• Tutorial D – a desktop database management system that implements Date & Darwen's "Tutorial D" database language (Rel)
• Datalog Educational System – deductive database system with Datalog, SQL, Relational Algebra, Tuple Relational Calculus and Domain Relational Calculus as query languages (DES)
• Sift – a basic, Relational Algebra based query engine built on top of Apache Arrow, drawing inspiration from Andy Grove's KQuery

ORM

• Pony – writes queries to the database using Python generator expressions and lambdas, analyzing the abstract syntax tree of the expression and translating it into a SQL query (SQLite, MySQL, PostgreSQL and Oracle)
• PINQ – write your database queries like queries on in-memory Python lists (uses SQLAlchemy)
• LINQ to SQL – a .NET component that provides a run-time infrastructure for managing relational data as objects

Using SQL

CLI

• OctoSQL – allows you to join, analyse and transform data from multiple databases and file formats using SQL
• dsq – execute SQL on JSON, CSV, Excel, Parquet, and more
• textql – execute SQL on structured text like CSV or TSV