Answers for "foreign key references constraint"

foreign key constraint

CREATE TABLE Students ( 	 /* Create table with foreign key - Way 1 */
    ID INT NOT NULL
    Name VARCHAR(255)
    LibraryID INT
    PRIMARY KEY (ID)
    FOREIGN KEY (Library_ID) REFERENCES Library(LibraryID)
);

CREATE TABLE Students ( 	 /* Create table with foreign key - Way 2 */
    ID INT NOT NULL PRIMARY KEY
    Name VARCHAR(255)
    LibraryID INT FOREIGN KEY (Library_ID) REFERENCES Library(LibraryID)
);


ALTER TABLE Students 	 /* Add a new foreign key */
ADD FOREIGN KEY (LibraryID)
REFERENCES Library (LibraryID);