Add DB create function

src/main/java/DB/DB.java

@@ -1,5 +1,6 @@
 package DB;
 
+import Exceptions.AlreadyOnTable;
 import Exceptions.NotFoundInTable;
 import lombok.Data;
 import lombok.Getter;
@@ -146,6 +147,32 @@ public class DB {
         }
     }
 
+    static public <T> T create(Class<T> cl, String table, String id, Map<String, String> values) throws AlreadyOnTable {
+        try {
+            if (exist(table, id, values.get(id)))
+                throw new AlreadyOnTable(values.get(id));
+            String query = String.format(
+                    "INSERT INTO "+table+" (%s) VALUES (%s)",
+                    String.join(",", values.keySet()),
+                    String.join(",", Collections.nCopies(values.values().size(), "?"))
+            );
+            PreparedStatement ps = DB.connection.prepareStatement(query);
+            int i = 1;
+            for (String value : values.values()) {
+                ps.setString(i, value);
+                i++;
+            }
+            int r = ps.executeUpdate();
+            ps.close();
+            if (r > 0)
+                return cl.getConstructor(String.class).newInstance(values.get(id));
+        } catch (SQLException | NoSuchMethodException | InstantiationException | IllegalAccessException | InvocationTargetException e) {
+            System.out.println(e);
+            return null;
+        }
+        return null;
+    }
+
     static public boolean delete(String table, String check, String checkValue) {
         try {
             PreparedStatement ps = DB.connection.prepareStatement("DELETE FROM "+table+" WHERE "+check+" = ?");

src/main/java/Exceptions/AlreadyOnTable.java

@@ -0,0 +1,5 @@
+package Exceptions;public class AlreadyOnTable extends Exception {
+    public AlreadyOnTable(String name) {
+        super(name+" is already on the table");
+    }
+}

src/main/java/ProjectionPlanning/Main.java

@@ -1,12 +1,27 @@
 package ProjectionPlanning;
 
 import DB.*;
+import Exceptions.AlreadyOnTable;
 import Exceptions.NotFoundInTable;
 
+import java.util.Collections;
+import java.util.Map;
+
 public class Main {
-    public static void main(String[] args) throws NotFoundInTable {
+    public static void main(String[] args) throws AlreadyOnTable {
         //new GUI();
         DB.connect();
-        System.out.println(new User("test@test.com").exist());
+        User u = DB.create(User.class,
+                "User",
+                "email",
+                Map.ofEntries(
+                        Map.entry("email", "test2@test.com"),
+                        Map.entry("firstName", "Test2"),
+                        Map.entry("lastName", "Test2"),
+                        Map.entry("phoneNumber", "0000000000")
+                )
+        );
+        System.out.println(u);
+        System.out.println(u.getFirstName());
     }
 }