added support for searching specific columns/fields 🚀

Author: ariflogs

CONTRIBUTING.md

@@ -1,9 +1,11 @@
 ## Before You Contribute
 
 ### Raise an Issue First
+
 Before you invest a significant amount of time on a change, please create a issue describing your proposal. This will help us to make sure that the change is in line with the project's goals, roadmap and avoid duplicate work.
 
 ### Avoid Dependencies
+
 We want to keep the project as lightweight as possible. So, please avoid adding any new dependencies unless it's absolutely necessary.
 
 ---
@@ -12,9 +14,9 @@ We want to keep the project as lightweight as possible. So, please avoid adding
 
 - Fork the repository on GitHub to your personal account.
 - Clone your forked repository to your local development environment.
-- Create a new branch for your feature or bug fix: ```git checkout -b your-branch-name```
-- Install the project dependencies: ```pnpm i```
-- Run the project in development mode: ```pnpm dev```
+- Create a new branch for your feature or bug fix: `git checkout -b your-branch-name`
+- Install the project dependencies: `pnpm i`
+- Run the project in development mode: `pnpm dev`
 - Make changes to your local repository.
 - Commit your changes and push them to your forked repository.
 - Open a pull request from your forked repository to the **dev branch** of this repository.
@@ -23,4 +25,4 @@ We want to keep the project as lightweight as possible. So, please avoid adding
 
 Your contributions are subject to the project's open-source(MIT) license. By submitting a PR, you agree to release your code under this license.
 
-## Thanks for your contribution!
+## Thanks for your contribution!

README.md

@@ -93,4 +93,5 @@ console.log(resp);
 - [ ] Typescript Support
 
 ## Contributing
+
 Read the [contributing guide](./CONTRIBUTING.md) to learn how you can contribute to this project.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "sql-to-nosql",
-  "version": "0.1.01",
+  "version": "0.1.02",
   "description": "Run SQL quries on your Mongodb database.",
   "repository": {
     "type": "git",

src/config/mapping.mts

@@ -1,13 +1,13 @@
 export const sqlToMongoDBcommandsMapping = {
-  select: "find", // s!
+  select: "find",
   insert: "insertMany",
   update: "updateMany",
   delete: "deleteMany",
 } as const;
 
 export const sqlToMongoDBoperatorsMapping = {
-  "=": "$eq", // s!
-  "!=": "$ne", // s!
+  "=": "$eq",
+  "!=": "$ne",
   ">": "$gt",
   "<": "$lt",
   ">=": "$gte",

src/index.mts

@@ -4,6 +4,7 @@ import { mappings } from "./config/mapping.mjs";
 import { parseQuery } from "./utils/parser.mjs";
 import { connect } from "./utils/database.mjs";
 import { SqlToNoSqlType } from "./types/index.mjs";
+import { MongoFindOperationType } from "types/nosql.mjs";
 
 export class SqlToNoSql {
   client: MongoClient | undefined;
@@ -22,29 +23,43 @@ export class SqlToNoSql {
 
     const q = parseQuery(query);
 
-    const filters: {
-      [key: string]: {
-        [operator: string]: string | number;
-      };
-    } = {};
+    if (q.command !== "select") {
+      throw new Error("Only select queries are supported");
+    }
+
+    const mongoQuery: MongoFindOperationType = {
+      collection: q.table,
+      [q.command]: mappings["mongodb"]["commands"][q.command],
+      query: {},
+      fields: {
+        // coz mongodb by default returns _id
+        _id: 0,
+      },
+    };
+
+    // Convert parsed columns to document fields
+    q.columns?.forEach((column) => {
+      if (column === "*") {
+        return;
+      }
+      if (column === "_id") {
+        mongoQuery.fields["_id"] = 1;
+        return;
+      }
+      mongoQuery.fields[column] = 1;
+    });
 
     // Convert parsed filters to MongoDB query
     q.filters?.forEach((filter) => {
       const { column, operator, value } = filter;
 
-      if (!filters[column]) {
-        filters[column] = {
+      if (!mongoQuery.query[column]) {
+        mongoQuery.query[column] = {
           [mappings["mongodb"]["operators"][operator]]: value,
         };
       }
     });
 
-    const mongoQuery = {
-      collection: q.table,
-      [q.command]: mappings["mongodb"]["commands"][q.command],
-      query: filters,
-    };
-
     try {
       if (!this.client) {
         this.client = await connect(this.config.connection);
@@ -54,9 +69,9 @@ export class SqlToNoSql {
       const db = this.client.db();
       const collection = db.collection(mongoQuery.collection);
 
-      const data = await collection[mongoQuery[q.command]](
-        mongoQuery.query,
-      ).toArray();
+      const data = await collection[mongoQuery[q.command]](mongoQuery.query, {
+        projection: mongoQuery.fields,
+      }).toArray();
 
       return data;
     } catch (err) {

src/types/nosql.mts

@@ -0,0 +1,21 @@
+import { mappings } from "config/mapping.mjs";
+import { SqlCommandOptions } from "./sql.mjs";
+
+export type MongoCommandOptions = "find" | "insertMany";
+
+export interface MongoQueryType {
+  [key: string]: {
+    [operator: string]: string | number;
+  };
+}
+
+export interface MongoFieldSelectionType {
+  [key: string]: 1 | 0;
+}
+
+export interface MongoFindOperationType {
+  select: (typeof mappings)["mongodb"]["commands"]["select"]; // sql -> mongodb
+  collection: string;
+  query: MongoQueryType;
+  fields: MongoFieldSelectionType;
+}

src/types/sql.mts

@@ -1,12 +1,14 @@
-interface filterType {
+export type SqlCommandOptions = "select" | "insert";
+
+interface FilterType {
   column: string;
   operator: "=";
   value: string | number;
 }
 
 export interface ParsedSqlType {
-  command: "select";
+  command: SqlCommandOptions;
   table: string;
   columns: string[];
-  filters: filterType[] | null;
+  filters: FilterType[] | null;
 }

src/utils/parser.mts

@@ -10,7 +10,8 @@ export const parseQuery = (query: string): ParsedSqlType => {
     filters: null,
   };
 
-  const [command, ...rest] = query.split(" ");
+  // for splliting by comma and space
+  const [command, ...rest] = query.split(/, |,| /);
 
   const lowerCaseCommand = command.toLowerCase();
   if (lowerCaseCommand !== "select") {