SQL

SQL Primary Key With Multiple Columns

CREATE TABLE Colleges (
  college_id INT,
  college_code VARCHAR(20),
  college_name VARCHAR(50),
  CONSTRAINT CollegePK PRIMARY KEY (college_id, college_code)
);

primary key multiple colums

ALTER TABLE Student
ADD CONSTRAINT PK_Student PRIMARY KEY (Rollno,LastName);

SQL Primary Key multiple column

ALTER TABLE Colleges
ADD CONSTRAINT CollegePK PRIMARY KEY (college_id, college_code);