ANSI SQL Query Validator

A simple command-line tool to validate SQL queries without executing them.

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What This Project Does

This tool checks if your SQL queries are written correctly. It's like a spell-checker for SQL code. It doesn't run the queries or connect to any database - it just checks if they follow proper SQL rules.

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Requirements

• Python 3.6 or higher
• No external libraries needed (uses only built-in Python modules)

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Project Structure

sql_validator/
├── main.py              # Start the program here
├── cli.py               # User interface
├── lexer.py             # Breaks SQL into pieces (tokens)
├── parser.py            # Checks if pieces are in correct order
├── validator.py         # Final validation checks
├── error_handler.py     # Manages errors
├── output_formatter.py  # Formats results
├── config.py            # Settings
├── app.py            # UI based app
├── test_queries.sql     # Sample queries to test
├── queries.sql     # Sample queries to test
├── implementation_guide.txt
├── test/
    ├── test_engine.py
    ├── test_lexer.py
    ├── conftest.py
    ├── test_parser.py
    ├── test_validator.py
└── README.md            # This file

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How to Run the Program

Step 1: Clone the Repository

Open your terminal or command prompt and run the following command to download the project:

git clone https://github.com/revathii-nair/sql-validator.git

Step 2: Enter the Project Directory

cd sql-validator

Step 3: Run the Program

python main.py

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How to Use the Validator

Once you run the program, you'll see a menu with 5 options:

Option 1: Validate Inline Query

This lets you type a SQL query directly.

Example:

Enter your choice: 1
Enter your SQL query:
SELECT name FROM users;

The program will tell you if it's valid or show errors.

Option 2: Validate from File

This validates all queries in a file.

Example:

Enter your choice: 2
Enter the path to SQL file: test_queries.sql

The program will check each query in the file.

Option 3: Configure Settings

Change how the validator works:

• SQL Dialect: Choose ANSI (default) or MSSQL
• Output Format: Choose text, json, or custom
• Strict Mode: Enable/disable extra checks

Option 4: Display Help

Shows information about supported SQL commands and usage tips.

Option 5: Exit

Quit the program.

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Supported SQL Commands

The validator supports these SQL commands:

DML (Data Manipulation)

• SELECT: Get data from tables
• INSERT: Add new data
• UPDATE: Change existing data
• DELETE: Remove data

DDL (Data Definition)

• CREATE TABLE: Make new tables
• DROP TABLE: Delete tables
• ALTER TABLE: Change table structure

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Example Queries

Valid Queries:

-- Simple SELECT
SELECT * FROM users;

-- SELECT with WHERE clause
SELECT name, age FROM users WHERE age > 18;

-- INSERT with all columns
INSERT INTO users (name, age) VALUES ('John', 25);

-- UPDATE with condition
UPDATE users SET age = 26 WHERE name = 'John';

-- DELETE with condition
DELETE FROM users WHERE age < 18;

-- CREATE TABLE
CREATE TABLE students (id INT, name VARCHAR);

-- DROP TABLE
DROP TABLE students;

-- ALTER TABLE
ALTER TABLE users ADD email VARCHAR;

Invalid Queries (These will show errors):

-- Missing semicolon
SELECT * FROM users

-- Missing FROM keyword
SELECT name WHERE age > 18;

-- Missing table name
SELECT * FROM;

-- Wrong column count in INSERT
INSERT INTO users (name) VALUES ('John', 25);

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Understanding the Output

Success Example:

============================================================
SQL QUERY VALIDATION RESULT
============================================================

Query: SELECT * FROM users;

Result: SUCCESS

Message: Query validated successfully
============================================================

Error Example:

============================================================
SQL QUERY VALIDATION RESULT
============================================================

Query: SELECT * FROM

Result: FAILED

--- ERRORS ---

Error ID: SYNTAX_001
Type: Syntax
Message: Expected IDENTIFIER but got KEYWORD at line 1, column 15
Line: 1, Column: 15
============================================================

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Output Formats

Text Format (Default)

Easy to read, good for viewing on screen.

JSON Format

Structured format, good for processing by other programs.

Example:

{
  "query": "SELECT * FROM users;",
  "success": true,
  "errors": [],
  "warnings": []
}

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Saving Results

After validation, the program asks:

Save output to file? (yes/no):

Type yes and enter a filename to save results.

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Testing the Validator

A test file test_queries.sql is included with sample queries.

To test:

1. Run the program: python main.py
2. Choose option 2 (Validate from file)
3. Enter: test_queries.sql
4. See results for all queries

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How It Works (Simple Explanation)

1. Lexer - Breaks your SQL into small pieces (like words in a sentence)
2. Parser - Checks if pieces are in the right order (like grammar check)
3. Validator - Applies SQL rules to make sure everything makes sense

Think of it like checking an essay:

• Lexer = Breaking into words
• Parser = Checking grammar
• Validator = Making sure it makes sense

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Project Limitations

• Does NOT execute queries
• Does NOT connect to databases
• Does NOT check if tables/columns actually exist
• Only validates syntax and structure

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UML DIAGRAMS

Sequence Diagram

Flow chart

Class Diagram

Componenet Diagram