tanpatil / sql_parser

SQL Query Parser/Executor for Python

Simple SQL query parser and executor for Python. Only supports SELECT statements with WHERE, and LIMIT on a single table.

Setup

Make sure you have pyparsing installed.

Usage:

Run main.py with the SQL query as a command line argument.

Here are some example queries:

Correct Select with Columns and Simple Where

• SELECT state, pop FROM table WHERE region = 'East';

Correct Select with All Columns (*)

• SELECT * FROM table;

Incorrect Select Statement (Misspelled Keyword)

• SELET state, region FROM table WHERE pop > 30;

Correct Select with Multiple Where Conditions

• SELECT region, pop_male, pop_female FROM table WHERE pop < 50 AND state = 'Texas';

Select with Non-existent Column Name

• SELECT city FROM table WHERE state = 'Florida';

Correct Select with Limit Clause

• SELECT state, pop FROM table LIMIT 5;

Select with Incorrect Limit Value (Non-integer)

• SELECT state, region FROM table LIMIT 'five';

Select with Complex Where Condition (AND, OR)

• SELECT state, pop FROM table WHERE (pop_male > 20 AND region = 'West') OR pop_female < 15;

Select with Incorrect Syntax in Where Clause

• SELECT state, pop_male FROM table WHERE pop >;

Correct Select with All Columns and No Where Clause

• SELECT * FROM table;

Faulty Spelling of SELECT

• SELEC state FROM table;

Incorrect/Missing Column Names

• SELECT non_existent_column FROM table;
• SELECT state, FROM table;

Multiple Columns

• SELECT state, region, pop FROM table;

Missing FROM Clause

• SELECT state WHERE pop > 20;

Incorrect Table Name

• SELECT state FROM non_existent_table;

Missing WHERE Clause

• SELECT state, pop;

Incorrect WHERE Clause

• SELECT state FROM table WHERE non_existent_column > 20;

Nested WHERE Clause

• SELECT state FROM table WHERE region = 'South' AND (pop > 20 OR pop_male > 10);

Missing LIMIT Clause

• SELECT state FROM table;

Incorrect LIMIT Clause

• SELECT state FROM table LIMIT twenty;

Large LIMIT Clause

• SELECT state FROM table LIMIT 1000000;

With and Without Parentheses

• SELECT state FROM table WHERE (region = 'South');
• SELECT state FROM table WHERE region = 'South';

Fail Silently

• SELECT state FROM table WHERE;