我有一個問題想出一個好的標題，但我現在解釋。從4個表中隨機挑選
我正在構建一個在線遊戲。我試圖建立摧毀武器的選項。
我有4種武器 - 攻擊，防禦，巡邏和間諜。巡邏和間諜武器有3個等級的武器，攻擊和防禦有15個等級。
我有一個表的每個類與col。命名爲w1，w2，w3，w4 ...和課程用戶的ID。
我給出了每個等級分數，所以w15例如值15分，w2值2分，我建立了一個函數來計算攻擊者將多少點摧毀到防禦者。
我卡在哪裏是如何隨機挑選武器？
假設攻擊者摧毀了100點武器。所以它可以是100級的巡邏兵1級，或25級武器，每級1級，或10級武器，排名第10。 我需要在類別（攻擊，防禦，巡邏和間諜）和武器之間隨機（w1 ，W2，W3 ..）。另外我需要的是在防守者擁有的武器數量的限制下，他不能再輸多少。
非常感謝！我知道我寫了一個很長的問題
我認爲這是一個邏輯問題，而不是處理表格的技術問題。如果您先處理邏輯，那麼您可以輕鬆地在桌上執行所需的操作。我們只需要知道每個項目有多少將隨機選擇使用（銷燬）。以下是在部分須藤碼/部分的PHP的隨機選擇方法：
1. Query database for available items and their relative values.
2. Store information as a multi-dimensional Array
3. Shuffle the Array
//in php
bool shuffle (array $itemsArray())
4. Iterate through each item in the array and add 1
to a variable for that item if, we have not reached our
limiting factors (amount available and cost vs remaining points).
Do this until all available points are allotted to a variable.
//in php
$i = 0;
do {
if ($itemsArray[$i][numAvail] > 0 &&
($availiblePoints - $itemsArray[$i][cost] >= $itemsArray[$i][cost]){
$$itemsArray[$i]++
//use of '$$' for variable variable
$availiblePoints-=$itemsArray[$i][cost];
}
else {
countSkips++
//need to keep track of how many items we skip
//if $availiblePoints is not zero yet but skips is size of array then
//we are done and have leftover points that cant be used.
}
$i++;
if ($i > count($itemsArray)) { $i=0; };
//start over if we have gone past the end of our Array
} while ($availiblePoints > 0 && $countSkips < count($itemsArray));
5. Logic Done. Now use the new variables to perform action on tables
由於陣列隨機洗牌，我們的結果是無論我們有多少點，都是隨機的。如果我們有100分，我們隨機數組中的第一項花費100分，或者前4項花費25分;隨機性將以任何方式完成其工作。
這只是概念。代碼可以進行一些改進，例如我們保存的變量實際上應該放在一個數組中，這樣當我們在表上執行操作時，我們就可以遍歷它們。
謝謝！完美的作品！ – OfirH 2014-10-17 08:44:56
太棒了。很高興我能夠幫助你通過它來思考:) 這是一個很好的問題。 – 2014-10-24 00:06:13
第一聯合的四個表這樣
SELECT * FROM (
SELECT * FROM w1
UNION
SELECT * FROM w2
UNION
SELECT * FROM w3
UNION
SELECT * FROM w4
)
然後計算出你的體重，功能，做一個隨機挑選
... ORDER BY RAND() LIMIT 5;
// randomly picks a number between 1 and 4
$randomWeapon = rand(1,4);
// Creates for ex. SELECT * FROM w1
$selectWeapon = mysqli($con, "SELECT * FROM w$randomWeapon"
基於我的其他提示這裏是一個解決方案，應該做的伎倆。
基本上，你首先隨機化所有waepons與他們的權重的用戶。如果你在這裏有NULL值，你應該取消選擇它們。 ORDER BY RAND()之後的巨大LIMIT是必要的，因爲我發現如果您不指定LIMIT，MySQL Optimizer將刪除隨機數。只要把它做得比整個桌子都要大。
其次，您通過運行變量對武器重量進行總和。
第三次從整個連續列表中選取損壞的數量。如果所需的傷害不完全匹配，您應該將其適應於一系列生命值。
-- 3. limit your sum to hitpoints
SELECT * FROM (
-- 2. now sum weaponWeight
SELECT weaponWeight, @prevWeight, @prevWeight:= weaponWeight + @prevWeight as cumulSum
FROM (
-- 1. shuffle all waepons of a user to do the random pick
SELECT weaponWeight FROM
(
-- attack
SELECT w1 as weaponWeight FROM attack WHERE ID = 'myUserID'
UNION
SELECT w2 as weaponWeight FROM attack WHERE ID = 'myUserID'
UNION
...
UNION
SELECT w15 as weaponWeight FROM attack WHERE ID = 'myUserID'
-- defence
UNION
SELECT w1 as weaponWeight FROM defence WHERE ID = 'myUserID'
UNION
...
UNION
SELECT w15 as weaponWeight FROM defence WHERE ID = 'myUserID'
-- patrol
UNION
SELECT w1 as weaponWeight FROM patrol WHERE ID = 'myUserID'
UNION
SELECT w2 as weaponWeight FROM patrol WHERE ID = 'myUserID'
UNION
SELECT w3 as weaponWeight FROM patrol WHERE ID = 'myUserID'
-- spy
UNION
SELECT w1 as weaponWeight FROM spy WHERE ID = 'myUserID'
UNION
SELECT w2 as weaponWeight FROM spy WHERE ID = 'myUserID'
UNION
SELECT w3 as weaponWeight FROM spy WHERE ID = 'myUserID'
)
ORDER BY RAND()
LIMIT 1000000000000 -- huge number here because Optimizer will remove random order otherwise
) as randomizedData,
(SELECT @prevWeight := 0) as a
) as sums
WHERE round(sums.cumulSum) = 100
好的...我用一張表邏輯表進行測試。只要結合（聯合）所有你想包括的東西。 （問題被標記用PHP，所以這是一個PHP溶液....）
<?php
$weapons = array(
array('name'=>'knife', 'type'=>'A', 'weight'=>5),
array('name'=>'sword', 'type'=>'A', 'weight'=>6),
array('name'=>'axe', 'type'=>'A', 'weight'=>3),
array('name'=>'handgun', 'type'=>'B', 'weight'=>7),
array('name'=>'rifle', 'type'=>'B', 'weight'=>5),
array('name'=>'cannon', 'type'=>'B', 'weight'=>2),
array('name'=>'mustard gas', 'type'=>'C', 'weight'=>7),
array('name'=>'agent orange', 'type'=>'C', 'weight'=>10),
array('name'=>'lewisite', 'type'=>'C', 'weight'=>5),
array('name'=>'mind', 'type'=>'D', 'weight'=>8),
// must have at least one thing with one... for this to work.
// i can definitely work on a solution that doesn't require this
// but it would take me a minute to think about it...
array('name'=>'words', 'type'=>'D', 'weight'=>1),
array('name'=>'hands', 'type'=>'D', 'weight'=>2),
array('name'=>'silent treatment','type'=>'D', 'weight'=>5),
);
$total_destroyed = 100;
$return = get_weapons($weapons, $weapons, $total_destroyed);
print_r($return);
function get_weapons($orig_weapons, $in_weapons, $n) {
// filter for only weapons w/ weight less than $n
$in_weapons = array_filter($in_weapons,
array(new LowerThanFilter($n),
'isLowerOrEq'));
$return = array();
if ($n > 0) {
if (empty($in_weapons)) {
$return = get_weapons($orig_weapons, $orig_weapons, $n);
}
else {
$found_it = array();
for ($i = 0; $i < count($in_weapons); $i++) {
$rand_index = array_rand($in_weapons);
$rand_weapon = $in_weapons[$rand_index];
if ($rand_weapon['weight'] <= $n) {
break;
}
}
$max_ct = floor($n/$rand_weapon['weight']);
$weapon_ct = rand(1,$max_ct);
$amount = $weapon_ct * $rand_weapon['weight'];
unset($in_weapons[$rand_index]);
$get_more = get_weapons($orig_weapons, $in_weapons, $n-$amount);
$return = $get_more;
$return[] = array_merge($rand_weapon, array(
'count' =>$count,
'amount'=>$amount));
}
}
return $return;
}
class LowerThanFilter {
// http://stackoverflow.com/a/5483168/623952
private $num;
function __construct($num) {
$this->num = $num;
}
function isLowerOrEq($i) {
return $i['weight'] <= $this->num;
}
}
?>
樣本輸出，其可以容易地重新排列。索引值是指原始$weapons數組索引。
Array
(
[0] => Array
(
[name] => words
[type] => D
[weight] => 1
[count] => 1
[amount] => 1
)
[1] => Array
(
[name] => knife
[type] => A
[weight] => 5
[count] => 2
[amount] => 10
)
[2] => Array
(
[name] => sword
[type] => A
[weight] => 6
[count] => 1
[amount] => 6
)
[3] => Array
(
[name] => agent orange
[type] => C
[weight] => 10
[count] => 2
[amount] => 20
)
[4] => Array
(
[name] => mustard gas
[type] => C
[weight] => 7
[count] => 9
[amount] => 63
)
)
試着這麼做：
$attackWeapon = array(/* weapon info comes here */ );
$defenseWeapon = array(/* weapon info comes here */);
$patrolWeapon = array(/* weapon info comes here */);
$spyWeapon = array(/* weapon info comes here */);
$rdmWeapon = mt_rand(1,4);
$attackLenght = count($attackWeapon);
$rdmAttackWeapon = mt_rand(0, $attackLenght-1);
$defenseLenght = count($defenseWeapon);
$rdmDefenseWeapon = mt_rand(0, $defenseLenght-1);
$patrolLenght = count($patrolWeapon);
$rdmPatrolWeapon = mt_rand(0, $patrolLenght-1);
$spyLenght = count($spyWeapon);
$rdmSpyLenght = mt_rand(0, $spyLenght-1);
If($rdmWeapon=1){
$dropWeapon = "attack";
echo $rdmAttackWeapon;
}
else if($rdmWeapon=2){
$dropWeapon = "defense";
echo $rdmDefenseWeapon;
}
else if($rdmWeapon=3){
$dropWeapon = "patrol";
echo $rdmPatrolWeapon
}
else($rdmWeapon=4){
$dropWeapon = "spy";
echo $rdmSpyWeapon;
}
It's簡單和愚蠢的，但對我的作品。
我會考慮架構更改。爲什麼不用一個武器表，武器類型列與涉及不同武器類型細節的表格有關？ – 2014-10-14 13:39:48
你可以請一個模式和樣本數據，與所需的輸出？ – 2014-10-14 13:59:14
你有多少列w1..w15？請在sql小提琴中提供架構。 – 2014-10-14 14:19:08