Avoiding database queries in Anylogic

Question

I would like to avoid costly repeated data base queries in Anylogic. I have seen the following thread in Stack Overflow What is the fastest way to look up continuous data on Anylogic (Java, SQL) where a simple three step answer is provided but I'm not sure what the second point of the three actually means:

2. Save all rows as instances of that class at model start-up into a map - you can use Origin/Destination as the key (use Anylogic's Pair object) and the class instance as the value

I have created a class that takes as inputs the information from each column of my database. I would now like to save each row as an instance of that class - is there an easy way to do this? I may be missing something simple as I'm new to Anylogic.

I'm also unsure of how to create a mapping, if anyone could add more detail to point 2 above I'd be very grateful!

Answer 1

this is effectively the best advice, you created the class, which is a great step, but now, one element of that class, will be used as the key... for example the name... for instance if your class has firstName as one variable and lastName as another variable, you will use a string that is the concatenation of firstName and lastName as your key. Of course any key is fine, assuming that it is unique for all your table. Also an integer as an id is ok too.

1. create a collection of type LinkedHashMap

2. Create a class (you did that)

3. Your collection will take as the key a String (first + last name) and as the value of the elment the class...

now, when you read your database you will have something like this:

for(Tuple t : yourQueryResults){
    YourClass yc=new YourClass(t.get(db.var1),t.get(db.var2));
    String totalName=t.get(db.first_name)+"_"+t.get(db.last_name);
    yourCollection.put(totalName,yc);
}

Now every time you want to find someone with the a name, for example "John Doe", instead of making a query, you will do

yourCollection.get("John_Doe").theVarYouWant;

if you use an id instead of the name, you can set an int as the key, and then you will just do yourCollection.get(theId).theVarYouWant