diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index e238864..78113b5 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -14,6 +14,7 @@ set(CORE_SOURCES
     seller.cpp
     article.cpp
     sale.cpp
+    marketplace.cpp
 )
 
 add_library(core STATIC ${CORE_SOURCES})
diff --git a/src/core/article.cpp b/src/core/article.cpp
index 74c00d9..42050e0 100644
--- a/src/core/article.cpp
+++ b/src/core/article.cpp
@@ -20,4 +20,8 @@ std::string Article::getDescription() { return description_; }
 
 Seller* Article::getSeller() { return sellerPtr_; }
 
-int Article::getPrice() { return price_; }
\ No newline at end of file
+int Article::getPrice() { return price_; }
+
+int Article::getArticleNo() {
+    return articleNo_;
+}
\ No newline at end of file
diff --git a/src/core/article.h b/src/core/article.h
index 5c78b80..a9ba3b8 100644
--- a/src/core/article.h
+++ b/src/core/article.h
@@ -24,6 +24,7 @@ class Article : public Entity
     //void setSeller(std::shared_ptr<Seller> sellerPtr);
     void setSeller(Seller* sellerPtr);
 
+    int getArticleNo();
     std::string getDescription();
     Seller* getSeller();
     int getPrice();
diff --git a/src/core/database.cpp b/src/core/database.cpp
index 43c82c3..e7b4168 100644
--- a/src/core/database.cpp
+++ b/src/core/database.cpp
@@ -145,7 +145,7 @@ void Database::beginTransaction() { exec("BEGIN TRANSACTION"); }
 
 void Database::endTransaction() { exec("END TRANSACTION"); }
 
-unsigned int Database::storeSellers(std::vector<Seller>& sellers)
+unsigned int Database::storeSellers(std::vector<std::shared_ptr<Seller>>& sellers)
 {
     int retCode{};
     int count{};
@@ -154,7 +154,7 @@ unsigned int Database::storeSellers(std::vector<Seller>& sellers)
     beginTransaction();
 
     for (auto& seller : sellers) {
-        if (seller.getState() == Entity::State::NEW) {
+        if (seller->getState() == Seller::State::NEW) {
             retCode = sqlite3_prepare_v2(
                 db_,
                 "INSERT INTO sellers"
@@ -165,16 +165,17 @@ unsigned int Database::storeSellers(std::vector<Seller>& sellers)
             if (retCode != SQLITE_OK)
                 throw std::runtime_error(sqlite3_errmsg(db_));
 
-            sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":uuid"),
-                              boost::uuids::to_string(seller.getUuid()).c_str(), -1, nullptr);
+            int test = sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":uuid"),
+                              boost::uuids::to_string(seller->getUuid()).c_str(), -1, SQLITE_TRANSIENT);
+            std::cout << "!!! TEST: " << test << "\n";
             sqlite3_bind_int(stmt, sqlite3_bind_parameter_index(stmt, ":seller_no"),
-                             seller.getSellerNo());
+                             seller->getSellerNo());
             sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":first_name"),
-                              seller.getFirstName().c_str(), -1, nullptr);
+                              seller->getFirstName().c_str(), -1, SQLITE_TRANSIENT);
             sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":last_name"),
-                              seller.getLastName().c_str(), -1, nullptr);
+                              seller->getLastName().c_str(), -1, SQLITE_TRANSIENT);
             sqlite3_bind_int(stmt, sqlite3_bind_parameter_index(stmt, ":num_offered_articles"),
-                             seller.numArticlesOffered());
+                             seller->numArticlesOffered());
 
             retCode = sqlite3_step(stmt);
 
@@ -184,12 +185,103 @@ unsigned int Database::storeSellers(std::vector<Seller>& sellers)
                 sqlite3_finalize(stmt);
                 throw std::runtime_error(errMsg);
             }
-            seller.setState(Seller::State::OK);
+            seller->setState(Seller::State::OK);
             ++count;
             sqlite3_finalize(stmt);
+        } else if (seller->getState() == Seller::State::UPDATE) {
+            // TODO
+            retCode = sqlite3_prepare_v2(
+                db_,
+                "UPDATE sellers SET"
+                " seller_no = :seller_no, first_name = :first_name,"
+                " last_name = :last_name, num_offered_articles = :num_offered_articles"
+                " WHERE id = :uuid",
+                -1, &stmt, nullptr);
+
+            if (retCode != SQLITE_OK)
+                throw std::runtime_error(sqlite3_errmsg(db_));
+
+            sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":uuid"),
+                              boost::uuids::to_string(seller->getUuid()).c_str(), -1, SQLITE_TRANSIENT);
+            sqlite3_bind_int(stmt, sqlite3_bind_parameter_index(stmt, ":seller_no"),
+                             seller->getSellerNo());
+            sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":first_name"),
+                              seller->getFirstName().c_str(), -1, SQLITE_TRANSIENT);
+            sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":last_name"),
+                              seller->getLastName().c_str(), -1, SQLITE_TRANSIENT);
+            sqlite3_bind_int(stmt, sqlite3_bind_parameter_index(stmt, ":num_offered_articles"),
+                             seller->numArticlesOffered());
+
+            retCode = sqlite3_step(stmt);
+
+            if (retCode != SQLITE_DONE) {
+
+                std::string errMsg(sqlite3_errmsg(db_));
+                sqlite3_finalize(stmt);
+                throw std::runtime_error(errMsg);
+            }
+            seller->setState(Seller::State::OK);
+            ++count;
+            sqlite3_finalize(stmt);
+        } else if (seller->getState() == Seller::State::DELETE) {
+            count += static_cast<int>(seller->getArticles(false).size());
+            // TODO
+        }
+
+        if (seller->getState() != Seller::State::DELETE) {
+            count += storeArticles(stmt, seller->getArticles(false));
         }
     }
 
     endTransaction();
+    return count;
+}
+
+unsigned int Database::storeArticles(sqlite3_stmt* stmt, std::vector<Article*> articles)
+{
+    int retCode{};
+    int count{};
+
+    for (auto& article : articles) {
+        if (article->getState() == Article::State::NEW) {
+            retCode = sqlite3_prepare_v2(
+                db_,
+                "INSERT INTO articles"
+                " (id, seller_id, source_no, article_no, description, price)"
+                " VALUES (:uuid, :seller_id, :source_no, :article_no, :desc, :price)",
+                -1, &stmt, nullptr);
+
+            if (retCode != SQLITE_OK)
+                throw std::runtime_error(sqlite3_errmsg(db_));
+
+            sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":uuid"),
+                              boost::uuids::to_string(article->getUuid()).c_str(), -1, SQLITE_TRANSIENT);
+            sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":seller_id"),
+                              boost::uuids::to_string(article->getSeller()->getUuid()).c_str(), -1,
+                              SQLITE_TRANSIENT);
+            sqlite3_bind_int(stmt, sqlite3_bind_parameter_index(stmt, ":source_no"),
+                             article->getSourceNo());
+            sqlite3_bind_int(stmt, sqlite3_bind_parameter_index(stmt, ":article_no"),
+                             article->getArticleNo());
+            sqlite3_bind_text(stmt, sqlite3_bind_parameter_index(stmt, ":desctiption"),
+                              article->getDescription().c_str(), -1, SQLITE_TRANSIENT);
+            sqlite3_bind_int(stmt, sqlite3_bind_parameter_index(stmt, ":price"),
+                             article->getPrice());
+
+            retCode = sqlite3_step(stmt);
+
+            if (retCode != SQLITE_DONE) {
+
+                std::string errMsg(sqlite3_errmsg(db_));
+                sqlite3_finalize(stmt);
+                throw std::runtime_error(errMsg);
+            }
+            article->setState(Seller::State::OK);
+            ++count;
+            sqlite3_finalize(stmt);
+        } else if (article->getState() == Article::State::UPDATE) {
+        }
+    }
+
     return count;
 }
\ No newline at end of file
diff --git a/src/core/database.h b/src/core/database.h
index 83fe27c..447fdb4 100644
--- a/src/core/database.h
+++ b/src/core/database.h
@@ -9,21 +9,23 @@
 
 class Database
 {
-public:
+  public:
     Database(const std::string& dbname);
     ~Database();
     Database(const Database&) = delete;
     Database& operator=(const Database&) = delete;
     void exec(const std::string& sql);
     void init();
-    unsigned int storeSellers(std::vector<Seller>& sellers);
-private:
-    sqlite3 *db_;
+    unsigned int storeSellers(std::vector<std::shared_ptr<Seller>>& sellers);
+
+  private:
+    sqlite3* db_;
     std::string dbname_;
     void beginTransaction();
     void endTransaction();
     void createNew();
     int getVersion();
+    unsigned int storeArticles(sqlite3_stmt* stmt, std::vector<Article*> articles);
 };
 
 #endif // DATABASE_H
\ No newline at end of file
diff --git a/src/core/entity.cpp b/src/core/entity.cpp
index 08614df..f203599 100644
--- a/src/core/entity.cpp
+++ b/src/core/entity.cpp
@@ -22,4 +22,12 @@ void Entity::setUuidFromString(const std::string& uuidString)
 inline Entity::State Entity::getState() const
 {
     return state_;
+}
+
+void Entity::setSourceNo(int sourceNo) {
+    sourceNo_ = sourceNo;
+}
+
+int Entity::getSourceNo() const {
+    return sourceNo_;
 }
\ No newline at end of file
diff --git a/src/core/entity.h b/src/core/entity.h
index 11890c6..7c37fbf 100644
--- a/src/core/entity.h
+++ b/src/core/entity.h
@@ -12,15 +12,20 @@ class Entity
     enum class State { NEW, UPDATE, DELETE, OK };
 
     virtual ~Entity() = 0;
-    const boost::uuids::uuid& getUuid() const { return uuid_; };
+
     void createUuid();
     void setUuidFromString(const std::string& uuidString);
-    virtual State getState() const;
     void setState(State state) { state_ = state; }
+    void setSourceNo(int sourceNo);
+
+    const boost::uuids::uuid& getUuid() const { return uuid_; };
+    virtual State getState() const;
+    virtual int getSourceNo() const;
 
   private:
     boost::uuids::uuid uuid_{};
     State state_{State::NEW};
+    int sourceNo_{};
 };
 
 #endif // ENTITY_H
\ No newline at end of file
diff --git a/src/core/marketplace.cpp b/src/core/marketplace.cpp
new file mode 100644
index 0000000..946e1ad
--- /dev/null
+++ b/src/core/marketplace.cpp
@@ -0,0 +1,9 @@
+#include "marketplace.h"
+#include "database.h"
+
+void Marketplace::storeToDb() {
+    const std::string DB_PATH{"/tmp/kima2.db"};
+
+    Database db(DB_PATH);
+    db.storeSellers(sellers_);
+}
\ No newline at end of file
diff --git a/src/core/marketplace.h b/src/core/marketplace.h
new file mode 100644
index 0000000..ba78564
--- /dev/null
+++ b/src/core/marketplace.h
@@ -0,0 +1,21 @@
+#ifndef MARKETPLACE_H
+#define MARKETPLACE_H
+
+#include "article.h"
+#include "sale.h"
+#include "seller.h"
+
+#include <vector>
+
+class Marketplace
+{
+  public:
+    void storeToDb();
+    void loadFromDb();
+  private:
+    std::vector<std::shared_ptr<Seller>> sellers_;
+    //std::vector<std::shared_ptr<Article>> articles_;
+    std::vector<std::shared_ptr<Sale>> sales_;
+};
+
+#endif
\ No newline at end of file
diff --git a/src/core/sale.cpp b/src/core/sale.cpp
index 92b0140..1da00fc 100644
--- a/src/core/sale.cpp
+++ b/src/core/sale.cpp
@@ -8,9 +8,33 @@ void Sale::addArticle(std::shared_ptr<Article> articlePtr)
     articles_.push_back(articlePtr);
 }
 
+std::vector<Article*> Sale::getArticles()
+{
+    std::vector<Article*> articles(articles_.size());
+    for (const auto& article : articles_) {
+        articles.push_back(article.get());
+    }
+
+    return articles;
+}
+
+void Sale::removeArticle(const Article* articlePtr)
+{
+    auto it = std::find_if(articles_.begin(), articles_.end(),
+                           [&articlePtr](auto art) { return art.get() == articlePtr; });
+    if (it != articles_.end()) {
+        (*it)->setSale(nullptr);
+        articles_.erase(it);
+    }
+}
+
 int Sale::sumInCents()
 {
     int sum = std::accumulate(articles_.begin(), articles_.end(), 0,
-                               [](int a, std::shared_ptr<Article> b) { return a + b->getPrice(); });
+                              [](int a, std::shared_ptr<Article> b) { return a + b->getPrice(); });
     return sum;
-}
\ No newline at end of file
+}
+
+std::string Sale::getTimestamp() { return timestamp_; }
+
+void Sale::setTimestamp(const std::string& timestamp) { timestamp_ = timestamp; }
\ No newline at end of file
diff --git a/src/core/sale.h b/src/core/sale.h
index 11253bd..f11f14c 100644
--- a/src/core/sale.h
+++ b/src/core/sale.h
@@ -5,17 +5,25 @@
 
 #include <vector>
 
-#include <boost/date_time.hpp>
+#include "boost/date_time/posix_time/posix_time.hpp"
 
 class Article;
 
 class Sale : public Entity
 {
   public:
-    int sumInCents();
     void addArticle(std::shared_ptr<Article> articlePtr);
+    void setTimestamp(const std::string& timestamp);
+
+    std::vector<Article*> getArticles();
+    std::string getTimestamp();
+    int sumInCents();
+
+    void removeArticle(const Article* articlePtr);
+
   private:
-    boost::posix_time::ptime systemTime_{boost::posix_time::second_clock::local_time()};
+    std::string timestamp_{
+        boost::posix_time::to_iso_extended_string(boost::posix_time::second_clock::local_time())};
     std::vector<std::shared_ptr<Article>> articles_{};
 };
 
diff --git a/test/test_database.cpp b/test/test_database.cpp
index e4052c4..1493a10 100644
--- a/test/test_database.cpp
+++ b/test/test_database.cpp
@@ -17,23 +17,28 @@ BOOST_AUTO_TEST_CASE(store_seller_fail)
 {
     Database db(":memory:");
     db.init();
-    std::vector<Seller> sellers;
-    sellers.push_back({});
-    sellers.push_back({});
+    std::vector<std::shared_ptr<Seller>> sellers;
+    sellers.push_back(std::make_shared<Seller>());
+    sellers.push_back(std::make_shared<Seller>());
     BOOST_CHECK_THROW(db.storeSellers(sellers), std::runtime_error);
 }
 BOOST_AUTO_TEST_CASE(store_sellers_succ)
 {
     Database db(":memory:");
     db.init();
-    std::vector<Seller> sellers;
-    Seller a{};
-    a.createUuid();
-    a.setSellerNo(1);
-    Seller b{};
-    b.createUuid();
-    b.setSellerNo(2);
-    BOOST_TEST(a.getUuid() != b.getUuid());
+    std::vector<std::shared_ptr<Seller>> sellers;
+    auto a = std::make_shared<Seller>();
+    a->createUuid();
+    a->setSellerNo(1);
+    auto b = std::make_shared<Seller>("Max", "Mustermann");
+    b->createUuid();
+    b->setSellerNo(2);
+    auto c = std::make_shared<Article>();
+    c->createUuid();
+    c->setPrice(500);
+    c->setDescription("Test");
+    b->addArticle(c);
+    BOOST_TEST(a->getUuid() != b->getUuid());
     sellers.push_back(a);
     sellers.push_back(b);
     BOOST_CHECK_NO_THROW(db.storeSellers(sellers));
@@ -43,14 +48,14 @@ BOOST_AUTO_TEST_CASE(seller_states)
 {
     Database db(":memory:");
     db.init();
-    std::vector<Seller> sellers;
-    Seller a;
-    a.setSellerNo(3);
-    a.createUuid();
+    std::vector<std::shared_ptr<Seller>> sellers;
+    auto a = std::make_shared<Seller>();
+    a->setSellerNo(3);
+    a->createUuid();
     sellers.push_back(a);
     std::cout << "Anzahl sellers: " << sellers.size() << "\n";
-    BOOST_TEST((sellers.at(0).getState() == Entity::State::NEW));
+    BOOST_TEST((sellers.at(0)->getState() == Entity::State::NEW));
     BOOST_TEST(db.storeSellers(sellers) == 1);
-    BOOST_TEST((sellers.at(0).getState() == Entity::State::OK));
+    BOOST_TEST((sellers.at(0)->getState() == Entity::State::OK));
     BOOST_TEST(db.storeSellers(sellers) == 0);
 }
\ No newline at end of file
diff --git a/test/test_sale.cpp b/test/test_sale.cpp
index 0ee1bed..7ef6bc4 100644
--- a/test/test_sale.cpp
+++ b/test/test_sale.cpp
@@ -30,4 +30,15 @@ BOOST_AUTO_TEST_CASE(articles_sum)
 
     BOOST_TEST(sale.sumInCents() == 550);
     BOOST_TEST(seller.getArticles(true).size() == 10);
+}
+
+BOOST_AUTO_TEST_CASE(remove_article) {
+    auto art = std::make_shared<Article>();
+    Sale sale{};
+
+    BOOST_TEST(art->isSold() == false);
+    sale.addArticle(art);
+    BOOST_TEST(art->isSold() == true);
+    sale.removeArticle(art.get());
+    BOOST_TEST(art->isSold() == false);
 }
\ No newline at end of file