ALTER TABLE table_name MODIFY column_name datatype NOT NULL;
ALTER TABLE table1 ALTER COLUMN column1 datatype NOT NULL;
CREATE TABLE Colleges (
college_id INT NOT NULL,
college_code VARCHAR(20),
college_name VARCHAR(50)
);
CREATE TABLE Persons (
ID int NOT NULL,
LastName varchar(255) NOT NULL,
FirstName varchar(255) NOT NULL,
Age int
);
CREATE TABLE Colleges (
college_id INT NOT NULL,
college_code VARCHAR(20) NOT NULL,
college_name VARCHAR(50)
);