diff --git a/src/databases/database.rs b/src/data/databases/database.rs
similarity index 59%
rename from src/databases/database.rs
rename to src/data/databases/database.rs
index e29673d..6e9733a 100644
--- a/src/databases/database.rs
+++ b/src/data/databases/database.rs
@@ -16,34 +16,27 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+use std::collections::HashMap;
+
 use super::tables::table::Table;
 
 #[derive(Debug)]
-pub struct Database {
-    pub name: String,
-    pub tables: Vec<Table>,
+pub struct Database<Value> {
+    pub tables: HashMap<String, Table<Value>>,
 }
 
-impl Database {
-    pub fn create_database(name: String) -> Self {
+impl<Value> Database<Value> {
+    pub fn create_database() -> Self {
         Self {
-            name,
-            tables: Vec::new(),
+            tables: HashMap::new(),
         }
     }
 
-    pub fn add_table(&mut self, name: String) {
-        self.tables.push(Table::create_table(name));
+    pub fn add_table(&mut self, name: &str, table: Table<Value>) {
+        self.tables.insert(name.to_string(), table);
     }
 
-    pub fn delete_table(&mut self, name: String) {
-        let mut ind = 0;
-        while ind != self.tables.len() {
-            if self.tables[ind].name == name {
-                self.tables.remove(ind);
-            } else {
-                ind += 1;
-            }
-        }
+    pub fn delete_table(&mut self, name: &str) {
+        self.tables.remove(name);
     }
 }
\ No newline at end of file
diff --git a/src/databases/tables/mod.rs b/src/data/databases/mod.rs
similarity index 94%
rename from src/databases/tables/mod.rs
rename to src/data/databases/mod.rs
index d583250..c6740c6 100644
--- a/src/databases/tables/mod.rs
+++ b/src/data/databases/mod.rs
@@ -16,5 +16,5 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pub(crate) mod table;
-pub(crate) mod rows;
\ No newline at end of file
+pub mod database;
+pub mod tables;
\ No newline at end of file
diff --git a/src/databases/mod.rs b/src/data/databases/tables/mod.rs
similarity index 93%
rename from src/databases/mod.rs
rename to src/data/databases/tables/mod.rs
index d1b8d37..0d4fd8b 100644
--- a/src/databases/mod.rs
+++ b/src/data/databases/tables/mod.rs
@@ -16,5 +16,5 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pub(crate) mod database;
-pub(crate) mod tables;
\ No newline at end of file
+pub mod table;
+pub mod rows;
\ No newline at end of file
diff --git a/src/databases/tables/rows/mod.rs b/src/data/databases/tables/rows/mod.rs
similarity index 97%
rename from src/databases/tables/rows/mod.rs
rename to src/data/databases/tables/rows/mod.rs
index 759536c..8260e80 100644
--- a/src/databases/tables/rows/mod.rs
+++ b/src/data/databases/tables/rows/mod.rs
@@ -16,4 +16,4 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pub(crate) mod row;
\ No newline at end of file
+pub mod row;
\ No newline at end of file
diff --git a/src/databases/tables/rows/row.rs b/src/data/databases/tables/rows/row.rs
similarity index 59%
rename from src/databases/tables/rows/row.rs
rename to src/data/databases/tables/rows/row.rs
index 4d108ac..87d9b3a 100644
--- a/src/databases/tables/rows/row.rs
+++ b/src/data/databases/tables/rows/row.rs
@@ -16,32 +16,25 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
+use std::collections::HashMap;
+
 #[derive(Debug)]
-pub struct Row {
-    pub primary_key: u32,
-    pub columns: Vec<String>,
+pub struct Row<Value> {
+    pub columns: HashMap<String, Value>,
 }
 
-impl Row {
-    pub fn create_row(primary_key: u32) -> Self {
+impl<Value> Row<Value> {
+    pub fn create_row() -> Self {
         Self {
-            primary_key,
-            columns: Vec::new(),
+            columns: HashMap::new(),
         }
     }
 
-    pub fn create_column(&mut self, name: String) {
-        self.columns.push(name);
+    pub fn create_column(&mut self, name: &str, value: Value) {
+        self.columns.insert(name.to_string(), value);
     }
 
-    pub fn delete_column(&mut self, name: String) {
-        let mut ind = 0;
-        while ind != self.columns.len() {
-            if self.columns[ind] == name {
-                self.columns.remove(ind);
-            } else {
-                ind += 1;
-            }
-        }
+    pub fn delete_column(&mut self, name: &str) {
+        self.columns.remove(name);
     }
 }
\ No newline at end of file
diff --git a/src/databases/tables/table.rs b/src/data/databases/tables/table.rs
similarity index 60%
rename from src/databases/tables/table.rs
rename to src/data/databases/tables/table.rs
index b880186..c6ce16f 100644
--- a/src/databases/tables/table.rs
+++ b/src/data/databases/tables/table.rs
@@ -16,34 +16,26 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-use crate::databases::tables::rows::row::Row;
+use std::collections::HashMap;
+use crate::data::databases::tables::rows::row::Row;
 
 #[derive(Debug)]
-pub struct Table {
-    pub name: String,
-    pub rows: Vec<Row>,
+pub struct Table<Value> {
+    pub rows: HashMap<u32, Row<Value>>,
 }
 
-impl Table {
-    pub fn create_table(name: String) -> Self {
+impl<Value> Table<Value> {
+    pub fn create_table() -> Self {
         Self {
-            name,
-            rows: Vec::new(),
+            rows: HashMap::new(),
         }
     }
 
-    pub fn add_row(&mut self, primary_key: u32) {
-        self.rows.push(Row::create_row(primary_key));
+    pub fn add_row(&mut self, primary_key: u32, row: Row<Value>) {
+        self.rows.insert(primary_key, row);
     }
 
     pub fn delete_row(&mut self, primary_key: u32) {
-        let mut ind = 0;
-        while ind != self.rows.len() {
-            if self.rows[ind].primary_key == primary_key {
-                self.rows.remove(ind);
-            } else {
-                ind += 1;
-            }
-        }
+        self.rows.remove(&primary_key);
     }
 }
\ No newline at end of file
diff --git a/src/data/mod.rs b/src/data/mod.rs
new file mode 100644
index 0000000..0adda9a
--- /dev/null
+++ b/src/data/mod.rs
@@ -0,0 +1 @@
+pub mod databases;
\ No newline at end of file
diff --git a/src/lib.rs b/src/lib.rs
index 8aeb6e9..5dd1738 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -16,33 +16,28 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-pub(crate) mod databases;
-use crate::databases::database::Database;
+pub mod data;
+use std::collections::HashMap;
+
+use crate::data::databases::database::Database;
 
 #[derive(Debug)]
-pub struct RNSQL {
-    pub databases: Vec<Database>,
+pub struct RNSQL<Value> {
+    pub databases: HashMap<String, Database<Value>>,
 }
 
-impl RNSQL {
+impl<Value> RNSQL<Value> {
     pub fn new() -> Self {
         Self {
-            databases: Vec::new(),
+            databases: HashMap::new(),
         }
     }
 
-    pub fn add_database(&mut self, name: String) {
-        self.databases.push(Database::create_database(name));
+    pub fn add_database(&mut self, name: &str, database: Database<Value>) {
+        self.databases.insert(name.to_string(), database);
     }
 
-    pub fn delete_database(&mut self, name: String) {
-        let mut ind = 0;
-        while ind != self.databases.len() {
-            if self.databases[ind].name == name {
-                self.databases.remove(ind);
-            } else {
-                ind += 1;
-            }
-        }
+    pub fn delete_database(&mut self, name: &str) {
+        self.databases.remove(name);
     }
 }
\ No newline at end of file
diff --git a/src/main.rs b/src/main.rs
index 76ef0b2..3122faa 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -15,42 +15,78 @@
  * You should have received a copy of the GNU General Public License
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
+
 use rapid_naive_sql::RNSQL;
- 
+use rapid_naive_sql::data::databases::database::Database;
+use rapid_naive_sql::data::databases::tables::table::Table;
+use rapid_naive_sql::data::databases::tables::rows::row::Row;
+
 fn main() {
+   const DB_NAME: &str = "db1";
+   const TB_NAME: &str = "tb1";
+   const RW_NAME: u32 = 1;
+   const CL_NAME: &str = "cl1";
+
    let mut project = RNSQL::new();
 
    println!("{:#?}\n\n", project);
 
-   project.add_database(String::from("db1"));
+   let db1 = Database::create_database();
+   project.add_database(DB_NAME, db1);
 
    println!("{:#?}\n\n", project);
 
-   project.databases[0].add_table(String::from("tb1"));
+   if let Some(database) = project.databases.get_mut(DB_NAME) {
+      let tb1 = Table::create_table();
+      database.add_table(TB_NAME, tb1);
+   }
 
    println!("{:#?}\n\n", project);
 
-   project.databases[0].tables[0].add_row(1);
+   if let Some(database) = project.databases.get_mut(DB_NAME) {
+      if let Some(table) = database.tables.get_mut(TB_NAME) {
+         let rw1 = Row::create_row();
+         table.add_row(RW_NAME, rw1);
+      }
+   }
 
    println!("{:#?}\n\n", project);
 
-   project.databases[0].tables[0].rows[0].create_column(String::from("name"));
+   if let Some(database) = project.databases.get_mut(DB_NAME) {
+      if let Some(table) = database.tables.get_mut(TB_NAME) {
+         if let Some(row) = table.rows.get_mut(&RW_NAME) {
+            row.create_column(CL_NAME, String::from("hello"));
+         }
+      }
+   }
 
    println!("{:#?}\n\n", project);
 
-   project.databases[0].tables[0].rows[0].delete_column(String::from("name"));
+   if let Some(database) = project.databases.get_mut(DB_NAME) {
+      if let Some(table) = database.tables.get_mut(TB_NAME) {
+         if let Some(row) = table.rows.get_mut(&RW_NAME) {
+            row.delete_column(CL_NAME);
+         }
+      }
+   }
 
    println!("{:#?}\n\n", project);
 
-   project.databases[0].tables[0].delete_row(1);
+   if let Some(database) = project.databases.get_mut(DB_NAME) {
+      if let Some(table) = database.tables.get_mut(TB_NAME) {
+         table.delete_row(RW_NAME);
+      }
+   }
 
    println!("{:#?}\n\n", project);
 
-   project.databases[0].delete_table(String::from("tb1"));
+   if let Some(database) = project.databases.get_mut(DB_NAME) {
+      database.delete_table(TB_NAME);
+   }
 
    println!("{:#?}\n\n", project);
 
-   project.delete_database(String::from("db1"));
+   project.delete_database(DB_NAME);
 
    println!("{:#?}", project);
 }
\ No newline at end of file