redis的一些命令和执行的返回值

普通写法

function get_chance($chance = [
    '和谐' => 3000,
    '爱国' => 5000,
    '敬业' => 110,
    '友善' => 1000,
    '富强' => 3000,
])
{
    $cardRange = [];
    $num = rand(0, array_sum(array_values($chance)));
    $total = 0;
    foreach ($chance as $key => $value) {
        $totalBefore = $total;
        $total += $value;
        if ($num >= $totalBefore && $num < $total) {
            return $key;
        }
        $cardRange[$key] = [$totalBefore, $total];
    }
    return $key;
}

在swoole环境中的写法, 兼容所有环境

function get_chance($chance = [
    '和谐' => 3000,
    '爱国' => 5000,
    '敬业' => 110,
    '友善' => 1000,
    '富强' => 3000,
])
{
    // 在协程中避免rand一段时间内值一致的问题
    $cardRange = [];
    $total = array_sum(array_values($chance));
    // $randValue = substr(explode(' ', microtime())[0], 0, 8);
    $randValue = strrev(substr(explode(' ', microtime())[0], 2, 6)) / 1000000;
    $rangeBefore = 0;
    $total2 = 0;
    foreach ($chance as $key => $value) {
        $total2 += $value;
        $rangeAfter = $total2 / $total;
        if ($randValue >= $rangeBefore && $randValue < $rangeAfter) {
            return $key;
        }
        $rangeBefore = $rangeAfter;
    }
    return $key;
}

校验数据和预期值的差异量

$t = [
    '记' => 300,
    '得' => 900,
    '我' => 150,
];
$r = [
    '记' => 0,
    '得' => 0,
    '我' => 0,
];
for ($k = 0; $k <= 10000; $k++) {
    $r[get_chance($t)]++;
}
var_dump($r);

正常的key查询哪些文档大家都能用, 但是如果key是 abc:de-fg 这样的值呢, 那么文档中那些办法无法实现查询了

尝试了好久, 终于找到了对应的解决办法

非法键值查询办法

比如demo为
json_data
{"abc:de-fg": "aa"}
那么取出这个值的办法为 json_data->'$."abc:de-fg"'
注意, 只能里面使用双引号的写法

JSON内的键值是否为null的判断方法

json_data
{"abc:de-fg": "aa","b":null}

// 判断里面的值等于null的判断方式
json_data->'$.b'=CAST('null' AS json)

业务场景
有一张表 project_users

表的数据列表
openid
------
[{"app_id": "1", "openid": "oromp5ZEhkLz1BXELF-cxyqap-uw"}, {"app_id": "2", "openid": "oKTQ41OqjJ848_SPe7wbTZO9RmOE"}]
[{"app_id": "1", "openid": "oromp5QBh9-a8VQlM99knmq2eM7k"}]
(NULL)

把表扁平化下来
SELECT 
uid
,openid
,openid->'$[*].app_id'
,json_search(openid->'$[*].app_id','all','2')
,openid->'$[0].openid'
,a.app_id
,a.json_openid
 FROM `project_users`,JSON_TABLE(openid, '$[*]' COLUMNS(app_id INT path '$.app_id',json_openid VARCHAR(50) path '$.openid')) a

-----

      uid  openid                                                                                                                  openid->'$[*].app_id'  json_search(openid->'$[*].app_id','all','2')  openid->'$[0].openid'           app_id  json_openid                   
---------  ----------------------------------------------------------------------------------------------------------------------  ---------------------  --------------------------------------------  ------------------------------  ------  ------------------------------
100001002  [{"app_id": "1", "openid": "oromp5ZEhkLz1BXELF-cxyqap-uw"}, {"app_id": "2", "openid": "oKTQ41OqjJ848_SPe7wbTZO9RmOE"}]  ["1", "2"]             "$[1]"                                        "oromp5ZEhkLz1BXELF-cxyqap-uw"       1  oromp5ZEhkLz1BXELF-cxyqap-uw  
100001002  [{"app_id": "1", "openid": "oromp5ZEhkLz1BXELF-cxyqap-uw"}, {"app_id": "2", "openid": "oKTQ41OqjJ848_SPe7wbTZO9RmOE"}]  ["1", "2"]             "$[1]"                                        "oromp5ZEhkLz1BXELF-cxyqap-uw"       2  oKTQ41OqjJ848_SPe7wbTZO9RmOE  
100001006  [{"app_id": "1", "openid": "oromp5QBh9-a8VQlM99knmq2eM7k"}]                                                             ["1"]                  (NULL)                                        "oromp5QBh9-a8VQlM99knmq2eM7k"       1  oromp5QBh9-a8VQlM99knmq2eM7k  

查询指定key

demo 数据包
data_cache
----------
{"courses:220-0": 24, "course_classes:1": 25701,"test":"666"}

如果我们查询test值或者移除非常简单
SELECT data_cache->'$.test',json_remove(data_cache,'$.test') FROM `daily_caches` WHERE id=32

result
data_cache->'$.test'  json_remove(data_cache,'$.test')                  
--------------------  --------------------------------------------------
"666"                 {"courses:220-0": 24, "course_classes:1": 25701}  


但是如果我们查询里面的 course_classes:1 key, 上面的方法就不行了, 需要下面的写法才行, 试了好久才试出来的

SELECT data_cache->'$."course_classes:1"',json_remove(data_cache,'$."course_classes:1"') FROM `daily_caches` WHERE id=32

result
data_cache->'$."course_classes:1"'  json_remove(data_cache,'$."course_classes:1"')  
----------------------------------  ------------------------------------------------
25701                               {"test": "666", "courses:220-0": 24}