diff --git a/modulo6/case4/.gitignore b/modulo6/case4/.gitignore
new file mode 100644
index 0000000..1586481
--- /dev/null
+++ b/modulo6/case4/.gitignore
@@ -0,0 +1,4 @@
+node_modules
+.env
+build
+package-lock.json
\ No newline at end of file
diff --git a/modulo6/case4/package.json b/modulo6/case4/package.json
new file mode 100644
index 0000000..8a27d1a
--- /dev/null
+++ b/modulo6/case4/package.json
@@ -0,0 +1,27 @@
+{
+  "name": "backend",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@types/knex": "^0.16.1",
+    "cors": "^2.8.5",
+    "dotenv": "^16.0.1",
+    "express": "^4.18.1",
+    "knex": "^2.2.0",
+    "mysql": "^2.18.1"
+  },
+  "devDependencies": {
+    "@types/cors": "^2.8.12",
+    "@types/express": "^4.17.13",
+    "@types/node": "^18.6.1",
+    "ts-node-dev": "^2.0.0",
+    "typescript": "^4.7.4"
+  }
+}
diff --git a/modulo6/case4/src/business/ProductBusiness.ts b/modulo6/case4/src/business/ProductBusiness.ts
new file mode 100644
index 0000000..e728fe6
--- /dev/null
+++ b/modulo6/case4/src/business/ProductBusiness.ts
@@ -0,0 +1,57 @@
+import { CustomError } from "../error/CustomError";
+import { Product } from "../model/Product";
+import { ProductDataInterface } from "../model/ProductDataInterface";
+import { GetProductResponse } from "../types/getProductResponse";
+import { RegisterProductInputDTO } from "../types/registerProductInputDTO";
+
+export default class ProductBusiness {
+    constructor (
+        private productData: ProductDataInterface
+    ) {}
+
+    async register (input: RegisterProductInputDTO) {
+        const { id, name, tags } = input
+
+        const productSameId = await this.productData.getProductById(id)
+        if (productSameId) {
+            throw new CustomError(409, "Product with this id already exists")
+        }
+        const productSameName = await this.productData.getProductByName(name)
+        if (productSameName) {
+            throw new CustomError(409, "Product with this name already exists")
+        }
+
+        const newProduct = new Product(id, name, tags)
+
+        await this.productData.insert(newProduct)
+
+        return name
+    }
+
+    async getById (id: number) {
+
+        if (!id || isNaN(id)) {
+            throw new CustomError(417, "Invalid id")
+        }
+
+        const result = await this.productData.getProductById(id)
+        if (!result) {
+            throw new CustomError(404, "Product not found")
+        }
+
+        return result
+    }
+
+    async search (searchInput: string) {
+        let result: GetProductResponse[]
+        if (!searchInput) {
+            result = await this.productData.getAllProducts()
+
+            return result
+        }
+
+        result = await this.productData.searchProducts(searchInput)
+
+        return result
+    }
+}
\ No newline at end of file
diff --git a/modulo6/case4/src/controller/ProductController.ts b/modulo6/case4/src/controller/ProductController.ts
new file mode 100644
index 0000000..3a71879
--- /dev/null
+++ b/modulo6/case4/src/controller/ProductController.ts
@@ -0,0 +1,62 @@
+import { Request, Response } from "express";
+import ProductBusiness from "../business/ProductBusiness";
+import { RegisterProductInputDTO } from "../types/registerProductInputDTO";
+
+export default class ProductController {
+    constructor (
+        private productBusiness: ProductBusiness
+    ) {}
+
+    register = async (req: Request, res: Response) => {
+        const {id, name, tags} = req.body
+
+        const input: RegisterProductInputDTO = {
+            id,
+            name,
+            tags
+        }
+        try {
+            const productName = await this.productBusiness.register(input)
+
+            res.status(201).send(`${productName} registered successfully`)
+            
+        } catch (error) {
+            if (error instanceof Error) {
+                return res.status(400).send(error.message)
+            }
+            res.status(500).send("Register error.")
+        }
+    }
+    
+    getById = async (req: Request, res: Response) => {
+        const id = Number(req.params.id)
+
+        try {
+            const product = await this.productBusiness.getById(id)
+
+            res.send({ product })
+            
+        } catch (error) {
+            if (error instanceof Error) {
+                return res.status(400).send(error.message)
+            }
+            res.status(500).send("Register error.")
+        }
+    }
+
+    search = async (req: Request, res: Response) => {
+        const searchInput = req.query.search as string
+
+        try {
+            const searchResult = await this.productBusiness.search(searchInput)
+
+            res.send({ productsFromSearch: searchResult })
+            
+        } catch (error) {
+            if (error instanceof Error) {
+                return res.status(400).send(error.message)
+            }
+            res.status(500).send("Register error.")
+        }
+    }
+}
\ No newline at end of file
diff --git a/modulo6/case4/src/data/BaseDatabase.ts b/modulo6/case4/src/data/BaseDatabase.ts
new file mode 100644
index 0000000..7511e05
--- /dev/null
+++ b/modulo6/case4/src/data/BaseDatabase.ts
@@ -0,0 +1,17 @@
+import knex from "knex";
+import dotenv from "dotenv"
+dotenv.config()
+
+export default abstract class BaseDatabase {
+    protected connection = knex({
+        client: 'mysql',
+        connection: {
+            host: process.env.DB_HOST,
+            user: process.env.DB_USER,
+            password: process.env.DB_PASSWORD,
+            database: process.env.DB_SCHEMA,
+            port: 3306,
+            multipleStatements: true
+        }
+    })
+}
\ No newline at end of file
diff --git a/modulo6/case4/src/data/ProductData.ts b/modulo6/case4/src/data/ProductData.ts
new file mode 100644
index 0000000..9e70c9b
--- /dev/null
+++ b/modulo6/case4/src/data/ProductData.ts
@@ -0,0 +1,81 @@
+import { Product } from "../model/Product";
+import { ProductDataInterface } from "../model/ProductDataInterface";
+import { productTableName } from "../model/TableNames";
+import { GetProductResponse } from "../types/getProductResponse";
+import BaseDatabase from "./BaseDatabase";
+
+export default class ProductData extends BaseDatabase implements ProductDataInterface {
+    private TABLE_NAME = productTableName
+    insert = async (product: Product) => {
+        try {
+            await this.connection(this.TABLE_NAME)
+                .insert(product)
+        } catch (error) {
+            if (error instanceof Error) {
+                throw new Error(error.message)
+            } else {
+                throw new Error("Database error.")
+            }
+        }
+    }
+
+    getProductByName = async (name: string) => {
+        try {
+            const queryResult: GetProductResponse[] = await this.connection(this.TABLE_NAME)
+                .where({ name })
+
+            return queryResult[0]
+        } catch (error) {
+            if (error instanceof Error) {
+                throw new Error(error.message)
+            } else {
+                throw new Error("Database error.")
+            }
+        }
+    }
+
+    getProductById = async (id: number) => {
+        try {
+            const queryResult: GetProductResponse[] = await this.connection(this.TABLE_NAME)
+                .where({ id })
+
+            return queryResult[0]
+        } catch (error) {
+            if (error instanceof Error) {
+                throw new Error(error.message)
+            } else {
+                throw new Error("Database error.")
+            }
+        }
+    }
+
+    searchProducts = async (search: string) => {
+        try {
+            const queryResult: GetProductResponse[] = await this.connection(this.TABLE_NAME)
+                .whereLike('name', `%${search}%`)
+                .orWhereLike('tag', `%${search}%`)
+
+            return queryResult
+        } catch (error) {
+            if (error instanceof Error) {
+                throw new Error(error.message)
+            } else {
+                throw new Error("Database error.")
+            }
+        }
+    }
+
+    getAllProducts = async () => {
+        try {
+            const queryResult: GetProductResponse[] = await this.connection(this.TABLE_NAME)
+
+            return queryResult
+        } catch (error) {
+            if (error instanceof Error) {
+                throw new Error(error.message)
+            } else {
+                throw new Error("Database error.")
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/modulo6/case4/src/error/CustomError.ts b/modulo6/case4/src/error/CustomError.ts
new file mode 100644
index 0000000..280f738
--- /dev/null
+++ b/modulo6/case4/src/error/CustomError.ts
@@ -0,0 +1,12 @@
+export class CustomError extends Error {
+
+    protected statusCode: number
+
+    constructor (
+        statusCode: number = 400,
+        message: string
+    ) {
+        super(message)
+        this.statusCode = statusCode
+    }
+}
\ No newline at end of file
diff --git a/modulo6/case4/src/index.ts b/modulo6/case4/src/index.ts
new file mode 100644
index 0000000..e69de29
diff --git a/modulo6/case4/src/model/Product.ts b/modulo6/case4/src/model/Product.ts
new file mode 100644
index 0000000..0dec3ec
--- /dev/null
+++ b/modulo6/case4/src/model/Product.ts
@@ -0,0 +1,7 @@
+export class Product {
+    constructor (
+        private id: number,
+        private name: string,
+        private tags: string[]
+    ) {}
+}
\ No newline at end of file
diff --git a/modulo6/case4/src/model/ProductDataInterface.ts b/modulo6/case4/src/model/ProductDataInterface.ts
new file mode 100644
index 0000000..544b402
--- /dev/null
+++ b/modulo6/case4/src/model/ProductDataInterface.ts
@@ -0,0 +1,14 @@
+import { GetProductResponse } from "../types/getProductResponse"
+import { Product } from "./Product"
+
+export interface ProductDataInterface {
+    insert: (product: Product) => Promise<void>
+
+    getProductByName: (name: string) => Promise<GetProductResponse>
+
+    getProductById: (id: number) => Promise<GetProductResponse>
+
+    searchProducts: (search: string) => Promise<GetProductResponse[]>
+
+    getAllProducts: () => Promise<GetProductResponse[]>
+}
\ No newline at end of file
diff --git a/modulo6/case4/src/model/TableNames.ts b/modulo6/case4/src/model/TableNames.ts
new file mode 100644
index 0000000..e077d2a
--- /dev/null
+++ b/modulo6/case4/src/model/TableNames.ts
@@ -0,0 +1 @@
+export const productTableName = 'products_amaro'
\ No newline at end of file
diff --git a/modulo6/case4/src/model/error/CustomError.ts b/modulo6/case4/src/model/error/CustomError.ts
new file mode 100644
index 0000000..280f738
--- /dev/null
+++ b/modulo6/case4/src/model/error/CustomError.ts
@@ -0,0 +1,12 @@
+export class CustomError extends Error {
+
+    protected statusCode: number
+
+    constructor (
+        statusCode: number = 400,
+        message: string
+    ) {
+        super(message)
+        this.statusCode = statusCode
+    }
+}
\ No newline at end of file
diff --git a/modulo6/case4/src/types/getProductResponse.ts b/modulo6/case4/src/types/getProductResponse.ts
new file mode 100644
index 0000000..82d9585
--- /dev/null
+++ b/modulo6/case4/src/types/getProductResponse.ts
@@ -0,0 +1,5 @@
+export type GetProductResponse = {
+    id: number,
+    name: string,
+    tags: string[]
+}
\ No newline at end of file
diff --git a/modulo6/case4/src/types/registerProductInputDTO.ts b/modulo6/case4/src/types/registerProductInputDTO.ts
new file mode 100644
index 0000000..f920366
--- /dev/null
+++ b/modulo6/case4/src/types/registerProductInputDTO.ts
@@ -0,0 +1,5 @@
+export type RegisterProductInputDTO = {
+    id: number,
+    name: string,
+    tags: string[]
+}
\ No newline at end of file
diff --git a/modulo6/case4/tsconfig.json b/modulo6/case4/tsconfig.json
new file mode 100644
index 0000000..5aa4d5f
--- /dev/null
+++ b/modulo6/case4/tsconfig.json
@@ -0,0 +1,13 @@
+{
+    "compilerOptions": {
+        "target": "es6",            /* Specify ECMAScript target version */
+        "module": "commonjs",       /* Specify module code generation */
+        "sourceMap": true,          /* Generates corresponding '.map' file. */
+        "outDir": "./build",        /* Redirect output structure to the directory. */
+        "rootDir": "./",         /* Specify the root directory of input files. */
+        "removeComments": true,    /* Do not emit comments to output. */
+        "noImplicitAny": true,       /* Raise error on declarations with an implied 'any' type. */
+        "esModuleInterop": true,  /*Pra quando da problema importando cors, express no topo do arquivo*/
+        "resolveJsonModule": true
+    }
+ }
\ No newline at end of file
diff --git a/modulo6/exercicios-logica/checa-parenteses/package.json b/modulo6/exercicios-logica/checa-parenteses/package.json
new file mode 100644
index 0000000..1780b3f
--- /dev/null
+++ b/modulo6/exercicios-logica/checa-parenteses/package.json
@@ -0,0 +1,13 @@
+{
+  "name": "checa-parenteses",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "start": "tsc && node ./build/index.js",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC"
+}
diff --git a/modulo6/exercicios-logica/checa-parenteses/src/index.ts b/modulo6/exercicios-logica/checa-parenteses/src/index.ts
new file mode 100644
index 0000000..67e0da9
--- /dev/null
+++ b/modulo6/exercicios-logica/checa-parenteses/src/index.ts
@@ -0,0 +1,64 @@
+function checaParenteses(str: string) {
+    let output = true
+    const parenteses = []
+    for (let char of str) {
+        if (char === '(' || char === '[' || char === '{') {
+            parenteses.push(char)
+        }
+        if (char === ')' || char === ']' || char === '}') {
+            let parenteseFechado = false
+            for (let i = parenteses.length - 1; i >= 0; i--) {
+                switch (char) {
+                    case ')':
+                        if (parenteses[i] === '(') {
+                            parenteseFechado = true
+                            parenteses.splice(i, 1)
+                            i = -1
+                        }
+                        if (parenteses[i] === '[' || parenteses[i] === '{') {
+                            output = false
+                            i = -1
+                        }
+                        break
+                    case ']':
+                        if (parenteses[i] === '[') {
+                            parenteseFechado = true
+                            parenteses.splice(i, 1)
+                            i = -1
+                        }
+                        if (parenteses[i] === '(' || parenteses[i] === '{') {
+                            output = false
+                            i = -1
+                        }
+                        break
+                    case '}':
+                        if (parenteses[i] === '{') {
+                            parenteseFechado = true
+                            parenteses.splice(i, 1)
+                            i = -1
+                        }
+                        if (parenteses[i] === '[' || parenteses[i] === '(') {
+                            output = false
+                            i = -1
+                        }
+                        break
+
+                }
+
+            }
+            if (!parenteseFechado) {
+                output = false
+            }
+        }
+    }
+    if (parenteses.length) {
+        output = false
+    }
+    return output
+}
+
+console.log(checaParenteses("()"));
+console.log(checaParenteses("()[]{}"));
+console.log(checaParenteses("(]"));
+console.log(checaParenteses("([)]"));
+console.log(checaParenteses("{[]}"));
diff --git a/modulo6/exercicios-logica/checa-parenteses/tsconfig.json b/modulo6/exercicios-logica/checa-parenteses/tsconfig.json
new file mode 100644
index 0000000..91829ea
--- /dev/null
+++ b/modulo6/exercicios-logica/checa-parenteses/tsconfig.json
@@ -0,0 +1,13 @@
+{
+    "compilerOptions": {
+        "target": "es6",            /* Specify ECMAScript target version */
+        "module": "commonjs",       /* Specify module code generation */
+        "sourceMap": true,          /* Generates corresponding '.map' file. */
+        "outDir": "./build",        /* Redirect output structure to the directory. */
+        "rootDir": "./src",         /* Specify the root directory of input files. */
+        "removeComments": true,    /* Do not emit comments to output. */
+        "noImplicitAny": true,       /* Raise error on declarations with an implied 'any' type. */
+        "esModuleInterop": true,  /*Pra quando da problema importando cors, express no topo do arquivo*/
+        "resolveJsonModule": true
+    }
+  }
\ No newline at end of file
diff --git a/modulo6/exercicios-logica/numero-solitario/package.json b/modulo6/exercicios-logica/numero-solitario/package.json
new file mode 100644
index 0000000..1780b3f
--- /dev/null
+++ b/modulo6/exercicios-logica/numero-solitario/package.json
@@ -0,0 +1,13 @@
+{
+  "name": "checa-parenteses",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "start": "tsc && node ./build/index.js",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC"
+}
diff --git a/modulo6/exercicios-logica/numero-solitario/src/index.ts b/modulo6/exercicios-logica/numero-solitario/src/index.ts
new file mode 100644
index 0000000..e6e970c
--- /dev/null
+++ b/modulo6/exercicios-logica/numero-solitario/src/index.ts
@@ -0,0 +1,16 @@
+function numeroSolitario (arr: number[]) {
+    const numeros: number[] = []
+    for (let num of arr) {
+        const i = numeros.indexOf(num)
+        if (i < 0) {
+            numeros.push(num)
+        } else {
+            numeros.splice(i, 1)
+        }
+    }
+
+    return numeros[0]
+}
+
+console.log(numeroSolitario([2,2,1]));
+console.log(numeroSolitario([4,1,2,1,2]));
diff --git a/modulo6/exercicios-logica/numero-solitario/tsconfig.json b/modulo6/exercicios-logica/numero-solitario/tsconfig.json
new file mode 100644
index 0000000..91829ea
--- /dev/null
+++ b/modulo6/exercicios-logica/numero-solitario/tsconfig.json
@@ -0,0 +1,13 @@
+{
+    "compilerOptions": {
+        "target": "es6",            /* Specify ECMAScript target version */
+        "module": "commonjs",       /* Specify module code generation */
+        "sourceMap": true,          /* Generates corresponding '.map' file. */
+        "outDir": "./build",        /* Redirect output structure to the directory. */
+        "rootDir": "./src",         /* Specify the root directory of input files. */
+        "removeComments": true,    /* Do not emit comments to output. */
+        "noImplicitAny": true,       /* Raise error on declarations with an implied 'any' type. */
+        "esModuleInterop": true,  /*Pra quando da problema importando cors, express no topo do arquivo*/
+        "resolveJsonModule": true
+    }
+  }
\ No newline at end of file
diff --git a/modulo6/exercicios-logica/prefixo-comum/package.json b/modulo6/exercicios-logica/prefixo-comum/package.json
new file mode 100644
index 0000000..1780b3f
--- /dev/null
+++ b/modulo6/exercicios-logica/prefixo-comum/package.json
@@ -0,0 +1,13 @@
+{
+  "name": "checa-parenteses",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "start": "tsc && node ./build/index.js",
+    "test": "echo \"Error: no test specified\" && exit 1"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC"
+}
diff --git a/modulo6/exercicios-logica/prefixo-comum/src/index.ts b/modulo6/exercicios-logica/prefixo-comum/src/index.ts
new file mode 100644
index 0000000..cbea49f
--- /dev/null
+++ b/modulo6/exercicios-logica/prefixo-comum/src/index.ts
@@ -0,0 +1,27 @@
+function prefixoComum (arr: string[]) {
+    let result = ''
+    let limite = Infinity
+    for (let str of arr) {
+        limite = Math.min(limite, str.length)
+    }
+    for (let i = 0; i < limite; i++) {
+        const char = arr[0][i]
+        let prefixoValido = true
+        for (let str of arr) {
+            if (str[i] !== char) {
+                prefixoValido = false
+            }
+        }
+        if (prefixoValido) {
+            result = result + char
+        } else {
+            break
+        }
+    }
+
+    return result
+}
+
+console.log(prefixoComum(["flower","flow","flight"]));
+console.log(prefixoComum(["dog","racecar","car"]));
+console.log(prefixoComum(["coracao","cor","corona","coreia"]));
diff --git a/modulo6/exercicios-logica/prefixo-comum/tsconfig.json b/modulo6/exercicios-logica/prefixo-comum/tsconfig.json
new file mode 100644
index 0000000..91829ea
--- /dev/null
+++ b/modulo6/exercicios-logica/prefixo-comum/tsconfig.json
@@ -0,0 +1,13 @@
+{
+    "compilerOptions": {
+        "target": "es6",            /* Specify ECMAScript target version */
+        "module": "commonjs",       /* Specify module code generation */
+        "sourceMap": true,          /* Generates corresponding '.map' file. */
+        "outDir": "./build",        /* Redirect output structure to the directory. */
+        "rootDir": "./src",         /* Specify the root directory of input files. */
+        "removeComments": true,    /* Do not emit comments to output. */
+        "noImplicitAny": true,       /* Raise error on declarations with an implied 'any' type. */
+        "esModuleInterop": true,  /*Pra quando da problema importando cors, express no topo do arquivo*/
+        "resolveJsonModule": true
+    }
+  }
\ No newline at end of file