Dynamic parameter JSON to WHERE in PHP - php

Question

I have JSON Response Request and want make one variable $Where from them, this the JSON pattern :
"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"}
Can anyone tell me how make thats patter to singgle row PHP variable like this :
$Where = "(NAMA = 'Rahmat' or NAMA = 'Rosadi') and (NIPK = '1919191919' or NIPK != '818181818181') and (JK='P' AND JK='L')"
Sorry for my bad english.

Answer 1

You can enumerate the filters list into PHP arrays, building each of them as a list of SQL OR values, then join them with implode(' OR ', ...); and further implode the arrays in a list of ' AND ' clauses.
This approach loses much of the flexibility allowed from your JSON setup, though; it can be extended to an AND-list of either OR-clauses or single clauses, and maybe coalesce OR clauses for the same field using the IN syntax, but not much more.
You can look to algorithm that convert from RPN notation to algebraic to look for a more powerful (albeit more complex) approach.
The simple version is
$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 ', $arr_Filters);
Using json_decode() an object can be retrieved that can be manipulated thus:
// ($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);