our second online sessionl of solver course

SQL session 5

	/*CREATe TABLE students (
  	   id int(20) NOT NULL,
  	   name VARCHAR(200),
  
  	   PRIMARY KEY (id)
    */
    /*CREATE TABLE results (
  	   id int(20) AUTO_INCREMENT,
       subject VARCHAR(100) NOT NULL,
  	   marks INT(3),
 	   PRIMARY KEY(id)
	);*/
    -- DROP TABLE payment;
   
    -- Add a new column to the results table
	-- The column name is student_id and it accepts integer values
	-- ALTER TABLE results
	-- COLUMN student_id INT NOT NULL;

	-- Make the student_id a foreign key
	-- ALTER TABLE results
	-- ADD FOREIGN KEY (student_id) REFERENCES students(id);
       
    -- Alter TABLE demo 
    -- ADD COLUMN student_id INT NOT NULL;
    
    -- ALTER TABLE demo
    -- ADD FOREIGN KEY (student_id) REFERENCES students(id);
	-- DROP TABLE results;
    /* CREATE TABLE results (
        id int NOT NULL AUTO_INCREMENT,
        subject VARCHAR(100) NOT NULL,
        marks INT(3),
        student_id INT(20),
        PRIMARY KEY(id),
        FOREIGN KEY (student_id) REFERENCES students(id)
        );
      */
     -- ALTER TABLE results
     -- DROP FOREIGN KEY student_id;
     -- ALTER TABLE results
     -- DROP INDEX student_id
       
      /*ALTER TABLE results
         ADD CONSTRAINT FK_student_id
         FOREIGN KEY (student_id) REFERENCES students(id);
       */
      
      /* ALTER TABLE results
          DROP FOREIGN KEY FK_student_id;
      */