在PHP中将动态参数JSON转换为WHERE

Question

我有JSON响应请求，想要从其中创建一个变量$ Where，这是JSON模式：

"filter":
{"filters":[
    {"logic":"and","filters":[
        {"field":"NAMA","operator":"eq","value":"Rahmat"},
        {"field":"NAMA","operator":"eq","value":"Rosadi"}
    ]},{"logic":"or","filters":[
        {"field":"NIPK","operator":"eq","value":"1919191919"},
        {"field":"NIPK","operator":"eq","value":"818181818181"}
    ]},{"logic":"and","filters":[
        {"field":"JK","operator":"eq","value":"P"},
        {"field":"JK","operator":"eq","value":"L"}
    ]}
],
"logic":"and"}

谁能告诉我如何让多数民众赞成在单个行PHP变量这样的模式：

$Where = "(NAMA = 'Rahmat' or NAMA = 'Rosadi') and (NIPK = '1919191919' or NIPK != '818181818181') and (JK='P' AND JK='L')"

对不起，我的英语不好。

Answer 1

您可以将filters列表枚举为PHP数组，将每个filters列表构建为SQL OR值列表，然后将它们与implode(' OR ', ...) ； 并在'AND'子句列表中内嵌该数组。

但是，这种方法失去了JSON设置所允许的许多灵活性。 它可以扩展到AND任-list OR -clauses或单条款，并可能合并OR条款使用相同的字段IN的语法，但没有更多。

您可以查看从RPN表示法转换为代数的算法，以寻找更强大（尽管更复杂）的方法。

简单的版本是

$ops = array(
    'eq' => '=',
    'ne' => '!=',
    'gt' => '>',
    'lt' => '<',
    'ge' => '>=',
    'le' => '<=',
    // CHECK THIS OUT, FIX & COMPLETE
);

$arr_Filters = array();
foreach($filters as $filter)
{
    /* $filter is a set of subfilters:
       {"logic":"and","filters":[
          {"field":"NAMA","operator":"eq","value":"Rahmat"},
         {"field":"NAMA","operator":"eq","value":"Rosadi"}
       ]},
       which we see as:
    */
    $logic = $filter['logic'];
    $arr_Filter  = array();
    foreach($filter['filters'] as $fov)
    {
        $op_f = $fov['operator'];
        $op   = $ops[$op_f];
        $value = /* FUNCTION TO SQL ESCAPE A VALUE */ $fov['value'];
        $value = is_numeric($value) ? $value : "'".$value."'";
        $arr_Filter[] = "$fov[field] $op $value";
    }
    $arr_Filters[] = '('.implode(' ' . $filter['logic'] . ' ', $arr_Filter).')';
}
$sql_filter = 'WHERE ' . implode(' AND ', $arr_Filters);

使用json_decode()可以检索可以进行操作的对象：

// ($ops omitted, same as above)

$arr_Filters = array();
foreach($filters->filter->filters as $filter)
{
    /* $filter is a set of subfilters:
       {"logic":"and","filters":[
          {"field":"NAMA","operator":"eq","value":"Rahmat"},
         {"field":"NAMA","operator":"eq","value":"Rosadi"}
       ]},
       which we see as:
    */
    $logic = $filter->logic;
    $arr_Filter  = array();
    foreach($filter->filters as $fov)
    {
        $op_f = $fov->operator;
        $op   = $ops[$op_f];
        $value = /* FUNCTION TO SQL ESCAPE A VALUE */ $fov->value;
        $value = is_numeric($value) ? $value : "'".$value."'";
        $arr_Filter[] = "{$fov->field} $op $value";
    }
    $arr_Filters[] = '('.implode(' ' . $filter->logic . ' ', $arr_Filter).')';
}
$sql_filter = 'WHERE ' . implode(' ' . $filters->filter->logic . ' ', $arr_Filters);