java - Storing a HashMap in an SQL database

Question

How do you store a HashMap inside of an SQL database? Also, how would you load that HashMap from a SQL database back into an instance of a HashMap?

Okay, this is what I'm doing. I have a database to store the player data for my game. It has a table containing their usernames and passwords. Each player has a HashMap that stores their properties. I need to store that HashMap in the database along with it's respective user.

Answer 1

You need a 3 column table

user,

key,

value

Would then look like

"user 1", "property1", "value1"

"user 1", "property2", "value2"

"user 2", "property1", "value1"

"user 3", "property1", "value1"

"user 3", "property2", "value2"

You would then just read the data back in and look round the user field to rebuild each has table.