diff --git a/BigCountries.sql b/BigCountries.sql
new file mode 100644
index 0000000..c3baf38
--- /dev/null
+++ b/BigCountries.sql
@@ -0,0 +1,2 @@
+SELECT NAME,POPULATION,AREA FROM WORLD
+WHERE AREA>= 3000000 OR POPULATION>=25000000;
\ No newline at end of file
diff --git a/DeleteDuplicateEmail.sql b/DeleteDuplicateEmail.sql
new file mode 100644
index 0000000..b08f066
--- /dev/null
+++ b/DeleteDuplicateEmail.sql
@@ -0,0 +1,3 @@
+
+DELETE P1 FROM PERSON P1
+CROSS JOIN PERSON P2 WHERE P1.EMAIL = P2.EMAIL and P1.ID >P2.ID
diff --git a/NthHighestSalary.sql b/NthHighestSalary.sql
new file mode 100644
index 0000000..ad476f3
--- /dev/null
+++ b/NthHighestSalary.sql
@@ -0,0 +1,9 @@
+CREATE FUNCTION getNthHighestSalary(N INT) RETURNS INT
+BEGIN
+    Declare m  int;
+    set m = (n-1);
+RETURN (
+    select distinct salary from employee order by salary desc 
+    limit m,1 
+);
+END
\ No newline at end of file