CODEWITHSUNDEEP
lua
Dyaxler
Dyaxler

Reputation: 21

Lua 5.0 - iterations over tables ignore duplicate keys even though values are different

Reading the injected comments in the Code Snippet should give enough context.

   --| Table |--
    QuestData = {
        ["QuestName"]={
            ["Quest Descrip"]={8,1686192712},
            ["Quest Descrip"]={32,1686193248},
            ["Quest Descrip"]={0,2965579272},
        },
    }


--| Code Snippet |--
--| gets QuestName then does below |--

    if QuestName then
        -- (K = QuestName) and (V = the 3 entries below it in the table)
        for k,v in pairs(QuestData) do
            -- Checks to make sure the external function that obtained the QuestName matches what is in the table before cont
            if strlower(k) == strlower(QuestName) then
                local index = 0
                -- Iterates over the first two pairs - Quest Descrip key and values
                for kk,vv in pairs(v) do
                    index = index + 1
                end
                -- Iterates over the second two pairs of values
                if index == 1 then
                    for kk,vv in pairs(v) do
                        -- Sends the 10 digit hash number to the function
                        Quest:Function(vv[2])
                    end
                end
            end
        end
    end

The issue I'm running into is that Lua will only pick up one of the numbers and ignore the rest. I need all the possible hash numbers regardless of duplicates. The QuestData table ("database") has well over 10,000 entries. I'm not going to go through all of them and remove the duplicates. Besides, the duplicates are there because the same quest can be picked up in more than one location in the game. It's not a duplicate quest but it has a different hash number.

Upvotes: 1

Views: 1661

Answers (3)

Roddy
Roddy

Reputation: 68033

You've said you can't "rewrite the database", but the problem is the QuestData table doesn't hold what you think it holds.

Here's your table:

QuestData = {
    ["QuestName"]={
        ["Quest Descrip"]={8,1686192712},
        ["Quest Descrip"]={32,1686193248},
        ["Quest Descrip"]={0,2965579272},
    },
}

But, this is actually like writing...

QuestData["Quest Descrip"] = {8,1686192712}
QuestData["Quest Descrip"] = {32,1686193248}
QuestData["Quest Descrip"] = {0,2965579272}

So the second (and then, third) values overwrite the first. The problem is not that you can't access the table, but that the table doesn't contain the values any more.

You need to find a different way of representing your data.

Upvotes: 1

Jakuje
Jakuje

Reputation: 25956

Key is always unique. It is the point of the key, that the key is pointing to unique value and you can't have more keys with same name to point different values. It is by definition by Lua tables.

It is like if you would want to have two variables with same name and different content. It does not make sense ...

The table type implements associative arrays. [...]

Like global variables, table fields evaluate to nil if they are not initialized. Also like global variables, you can assign nil to a table field to delete it. That is not a coincidence: Lua stores global variables in ordinary tables.

Quote from Lua Tables

Hashing in Lua

Based on comments, I update the answer to give some idea about hashing.

You are using hashing usually in low-level languages like C. In Lua, the associative arrays are already hashed somehow in the background, so it will be overkill (especially using SHA or so).

Instead of linked lists commonly used in C, you should just construct more levels of tables to handle collisions (there is nothing "better" in Lua).

And if you want to have it fancy set up some metatables to make it somehow transparent. But from your question, it is really not clear how your data look like and what you really want.

Basically you don't need more than this:

QuestData = {
    ["QuestName"]={
        ["Quest Descrip"]={
            {8,1686192712},
            {32,1686193248},
            {0,2965579272},
         },
    },
}

Upvotes: 6

Piglet
Piglet

Reputation: 28950

As Jakuje already mentioned table keys are unique. But you can store both as a table member like:

   QuestData = {
    -- "QuestName" must be unique! Of course you can put it into a table member as well
    ["QuestName"]={
       {hash = "Quest Descrip", values = {8,1686192712} },
       {hash = "Quest Descrip", values = {32,1686193248} },
       {hash = "Quest Descrip", values = {0,2965579272} }

        }
    }

I'm sure you can organize this in a better way. It looks like a rather confusing concept to me.

Upvotes: 1

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