node-simple-mssql-parser

A simple, lightweight parser for MSSQL (T-SQL) SELECT, UPDATE and INSERT statements in Node.js. It parses SQL queries into an Abstract Syntax Tree (AST) and provides utilities to traverse and analyze the AST for filtering, transformation, or inspection.

Use Cases

• Parse MSSQL SELECT and INSERT queries into a structured AST for further analysis or transformation.
• Traverse the AST to filter, select, or modify nodes (e.g., extract columns, rewrite queries, static analysis).
• Useful for query analysis tools, code generation, query rewriting, or building SQL-aware applications.

Installation

# Using pnpm
pnpm add node-simple-mssql-parser
# or npm
npm install node-simple-mssql-parser

Basic Usage

Parse a SELECT Query

import { parseMSSQLStatement } from "node-simple-mssql-parser";

const sql = "SELECT id, name FROM [dbo].[users];";
const ast = parseMSSQLStatement(sql);
console.log(JSON.stringify(ast, null, 2));

Traverse the AST

import { traverse } from "node-simple-mssql-parser";

traverse(ast, {
  enter(node) {
    if (node.kind === "column") {
      console.log("Column:", node.name.name);
    }
  },
});

Example: Extracting All Column Names

const columns = [];
traverse(ast, {
  enter(node) {
    if (node.kind === "column") {
      columns.push(node.name.name);
    }
  },
});
console.log(columns); // ["id", "name"]

Parse and Traverse an INSERT Statement

Pretty-print a SQL AST

import { parseMSSQLStatement, prettyPrint } from "node-simple-mssql-parser";

const sql = "SELECT id, name FROM [dbo].[users];";
const ast = parseMSSQLStatement(sql);
const formatted = prettyPrint(ast);
console.log(formatted);

const sql = "INSERT INTO [dbo].[users] (name, age) VALUES ('Alice', 30);";
const ast = parseMSSQLStatement(sql);
traverse(ast, {
  enter(node) {
    if (node.kind === "insert") {
      console.log("Insert target:", node.target.table.name);
    }
    if (node.kind === "column") {
      console.log("Column:", node.name.name);
    }
    if (node.kind === "literal") {
      console.log("Value:", node.value);
    }
  },
});

Features

• Parse MSSQL SELECT, INSERT, and UPDATE statements into a rich, typed AST
• Traverse and analyze the AST with a flexible visitor utility
• Supports WHERE conditions with nested AND/OR and grouping (parentheses)
• Joins: INNER, LEFT OUTER, RIGHT OUTER
• Column and table aliases
• Functions: COUNT(*), COUNT(column), and NEWID()
• GROUP BY, ORDER BY, OFFSET, LIMIT
• Output clause for INSERT and UPDATE
• TypeScript types for all AST nodes
• Pretty-printing: Convert AST back to formatted SQL
• Error reporting for invalid SQL syntax

Example SQL features supported:

• SELECT id, name FROM [dbo].[users] WHERE id = 5 AND (a.b = @input OR columnName2 = 'hello')
• INSERT INTO [dbo].[users] (name, age) OUTPUT inserted.id VALUES ('Alice', 30);
• UPDATE [dbo].[users] SET name = 'Bob' WHERE id = 1;
• SELECT COUNT(*) FROM [dbo].[users]
• SELECT * FROM [dbo].[users] u JOIN [dbo].[posts] p ON u.id = p.user_id

See the test files for more advanced usage and edge cases.

License

MIT