Setting Default Values

CODE: Setting Default Values 

Define a table with a DEFAULT name specified:

CREATE TABLE cats3
  (
    name VARCHAR(20) DEFAULT 'no name provided',
    age INT DEFAULT 99
  );

Notice the change when you describe the table:

DESC cats3; 

Insert a cat without a name:

INSERT INTO cats3(age) VALUES(13); 

Or a nameless, ageless cat:

INSERT INTO cats3() VALUES(); 

Combine NOT NULL and DEFAULT:

CREATE TABLE cats4
  (
    name VARCHAR(20) NOT NULL DEFAULT 'unnamed',
    age INT NOT NULL DEFAULT 99
  );

  
Notice The Difference:

INSERT INTO cats() VALUES();
 
SELECT * FROM cats;
 
INSERT INTO cats3() VALUES();
 
SELECT * FROM cats3;
 
INSERT INTO cats3(name, age) VALUES('Montana', NULL);
 
SELECT * FROM cats3;
 
INSERT INTO cats4(name, age) VALUES('Cali', NULL);