MySQL - Populate table column with values from another table - mysql

Question

Need some help please. Creating a basic relational database and trying to add column values from my account table to my login table. However, bit stuck on how to achieve this. I'm trying to take the AccountID, Username, Sign_in data to populate the Login table but nothing appear when executed.
my code:
CREATE TABLE IF NOT EXISTS Account
(
AccountID int NOT NULL AUTO_INCREMENT,
Title VARCHAR(64) NOT NULL,
FirstName varchar(16) NOT NULL,
LastName varchar(32) NOT NULL,
DOB DATE,
Email VARCHAR(255),
Username varchar(32) UNIQUE NOT NULL,
Sign_in varchar(32) UNIQUE NOT NULL,
PRIMARY KEY (AccountID)
);
ALTER TABLE Account AUTO_INCREMENT=1;
CREATE TABLE IF NOT EXISTS Login
(
LoginID int NOT NULL AUTO_INCREMENT PRIMARY KEY,
AccountID INT NOT NULL,
Username varchar(32) NOT NULL,
Sign_in varchar(32) NOT NULL,
LoginDate TIMESTAMP(6),
FOREIGN KEY (AccountID) REFERENCES Account(AccountID),
FOREIGN KEY (Username) REFERENCES Account(Username),
FOREIGN KEY (Sign_in) REFERENCES Account(Sign_in)
);
ALTER TABLE Login AUTO_INCREMENT=100;
and tried the query (edited from a similar query found on this forum) to no avail
INSERT INTO Login
(
AccountID,
Username,
Sign_in
)
SELECT
a.AccountID, a.Username, a.Sign_in
FROM Account a
INNER JOIN Login
ON a.AccountID = l.AccountID;
Select * from Login;
Help/advice appreciated.

Answer 1

You are missing the point of relational databases. You simply want to map to the primary key and then look up the other values. You don't want to store the values in two places.
So:
CREATE TABLE IF NOT EXISTS Account (
AccountID int AUTO_INCREMENT PRIMARY KEY,
Title VARCHAR(64) NOT NULL,
FirstName varchar(16) NOT NULL,
LastName varchar(32) NOT NULL,
DOB DATE,
Email VARCHAR(255),
Username varchar(32) UNIQUE NOT NULL,
Sign_in varchar(32) UNIQUE NOT NULL
);
CREATE TABLE IF NOT EXISTS Login (
LoginID int NOT NULL AUTO_INCREMENT PRIMARY KEY,
AccountID INT NOT NULL,
LoginDate TIMESTAMP(6),
FOREIGN KEY (AccountID) REFERENCES Account(AccountID)
);
Then if you want the username or sign_in, you use a JOIN to look up that information.
I don't see a reason to set the auto-increment values. There is generally no problem having them start at 1 in all tables.

Answer 2

Managed to work it out...
INSERT INTO Login (AccountID, Username, Sign_in)
SELECT AccountID, Username, Sign_in
FROM Account;
Did take on board the advice regarding the Primary Key ID suggestion though. Cheers