KullGames TinySQL

A real recursive-descent SQL parser plus a relational-algebra executor. Each query below is parsed into a Scan/Selection/Projection algebra tree and evaluated live at build time by OnlyCSharp 1.8 DataScience.Databases.DatabaseTheory (SqlParser + RelationalAlgebra) - no query logic lives in this page.

Table "employees" (6 rows)

name	dept	salary
Alice	Engineering	72000
Bob	Sales	58000
Carol	Engineering	95000
Dave	Sales	45000
Eve	Engineering	61000
Frank	Marketing	83000

Queries

SQL> SELECT name, salary FROM employees WHERE salary > 60000

name	salary
Alice	72000
Carol	95000
Eve	61000
Frank	83000

(4 row(s), 2 column(s))

SQL> SELECT * FROM employees WHERE dept = 'Engineering'

name	dept	salary
Alice	Engineering	72000
Carol	Engineering	95000
Eve	Engineering	61000

(3 row(s), 3 column(s))

SQL> SELECT name FROM employees WHERE salary < 50000

name
Dave

(1 row(s), 1 column(s))