All Manipulation Query.

Author: atomicno28

15. DML Complete.sql

@@ -0,0 +1,35 @@
+-- INSERT
+insert into Student(Roll,Fname,Lname,Class) values(1,"Nikhil","Patel","Final Year");
+insert into Student Values(2,"Brahmeshwar","Thakur","Final Year");
+
+-----------------------------------------
+-- UPDATE
+update Student SET Roll = 31 where fname="Nikhil";
+--( to update multiple rows)
+update Student set Roll = Roll + 1;
+
+-- to support Referntial Integrity. 
+ON UPDATE CASCADE;
+
+
+-- Can be added to the table while creating constraints. Suppose there is a situation where we have two tables
+--such that primary key of one table is the foreign key for another table. if we update the primary key of the first
+--  table then using the ON UPDATE CASCADE foreign key of the second table automatically get updated.
+-----------------------------------------
+
+-- DELETE 
+
+-- delete the row of roll 45
+delete from Student where Roll=45;
+
+-- delete all rows
+delete from Student;
+
+-- to support Referential Integrity.
+foreign key (Cust_ID) REFERENCE Student(Stud_ID) ON DELETE SET NULL;
+
+-------------------
+
+-- REPLACE (primarily use for always present tuples)
+
+