https://github.com/vkazanov/sql-interpreters-post
PigletQL - example SQL-like language interpreter
https://github.com/vkazanov/sql-interpreters-post
Last synced: 3 months ago
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PigletQL - example SQL-like language interpreter
- Host: GitHub
- URL: https://github.com/vkazanov/sql-interpreters-post
- Owner: vkazanov
- License: gpl-3.0
- Created: 2019-03-08T07:55:43.000Z (over 6 years ago)
- Default Branch: master
- Last Pushed: 2020-01-22T15:22:45.000Z (over 5 years ago)
- Last Synced: 2025-03-15T01:47:49.352Z (3 months ago)
- Language: C
- Homepage:
- Size: 5.59 MB
- Stars: 16
- Watchers: 2
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: README.org
- License: LICENSE
Awesome Lists containing this project
README
* PigletQL - a tiny SQL-like interpreter
PigletQL is a tiny SQL-like language featuring a single value type, three kinds of queries (CREATE
TABLE, INSERT, SELECT) and a Volcano-style (see the "Volcano - an extensible and parallel query
evaluation system" paper) interpreter. It does not do any optimization and keeps all data in
memory.
It was created as an example language for an article ([[https://habr.com/ru/company/badoo/blog/461699/][Russian]], [[https://badootech.badoo.com/volcanic-piglet-or-do-it-yourself-sql-65357cd9d891][English]]) on SQL interpreter
architecture.
* Building
It should be trivial to compile the interpreter on Linux using a recent GCC. Just clone the repo
and do:
#+BEGIN_EXAMPLE
> make
> make test
> ./pigletql
> # your query here
#+END_EXAMPLE
* Example queries
#+BEGIN_EXAMPLE
> ./pigletql
> create table rel1 (a1,a2,a3);
> insert into rel1 values (1,2,3);
> insert into rel1 values (4,5,6);
> select a1 from rel1;
a1
1
4
rows: 2
>
#+END_EXAMPLE
#+BEGIN_EXAMPLE
> ./pigletql
> create table rel1 (a1,a2,a3);
> insert into rel1 values (1,2,3);
> insert into rel1 values (4,5,6);
> select a1 from rel1 where a1 > 3;
a1
4
rows: 1
>
#+END_EXAMPLE
#+BEGIN_EXAMPLE
> ./pigletql
> create table rel1 (a1,a2,a3);
> insert into rel1 values (1,2,3);
> insert into rel1 values (4,5,6);
> select a1 from rel1 order by a1 desc;
a1
4
1
rows: 2
#+END_EXAMPLE
#+BEGIN_EXAMPLE
> ./pigletql
> create table rel1 (a1,a2,a3);
> insert into rel1 values (1,2,3);
> insert into rel1 values (4,5,6);
> create table rel2 (a4,a5,a6);
> insert into rel2 values (7,8,6);
> insert into rel2 values (9,10,6);
> select a1,a2,a3,a4,a5,a6 from rel1, rel2 where a3=a6;
a1 a2 a3 a4 a5 a6
4 5 6 7 8 6
4 5 6 9 10 6
rows: 2
#+END_EXAMPLE
* Code structure
- [[file:pigletql-eval.h][pigletql-eval.h]] - evaluation engine, i.e. Volcano-style operators, relations, tuples, etc
- [[file:pigletql-parser.h][pigletql-parser.h]] - lexer/parser
- [[file:pigletql-validate.h][pigletql-validate.h]] - query validation logic
- [[file:pigletql-catalogue.h][pigletql-catalogue.h]] - a catalogue of relations available
- [[file:pigletql-def.h][pigletql-def.h]] - constants and helpers
- [[file:pigletql.c][pigletql.c]] - putting everything together