MySQL - 从子查询更新列

Question

Can't get this to work. I have a table 'Players' which has a primary key 'Id' and among others, a 'Name' column. Another table 'Bookings' has a column 'PlayerId' which references 'Players.Id'.

I have just added a column 'Name' to 'Bookings' which needs to contain an actual copy of the player's name.

I am trying set fill in all the names in Bookings using the following statement:

UPDATE Bookings SET Name = (SELECT Name FROM Players WHERE Players.Id=Bookings.PlayerId);

but what I get is error 1263: "Column set to default value; NULL supplied to NOT NULL column 'Name' at row 0".

What have I done wrong?

Answer 1

Try this:

update Bookings, Players
set Bookings.Name = Players.Name
where Bookings.playerId = Players.Id

You have to be sure that there's a one to one relation between Players and Bookings (it's the only way I think this makes any sense).

Answer 2

Use MYSQL UPDATE JOIN for this purpose. This is the query you need:

UPDATE Bookings
LEFT JOIN Players
ON Players.Id=Bookings.PlayerId
SET Bookings.Name = Players.Name