在将大型(cca 60mb )geojson存储到数据库之前，我使用这个代码对它进行编码：
// controller
public function importZones () {
ini_set('max_execution_time', '0');
ini_set('memory_limit', '-1');
ini_set("precision", -1);
ini_set("serialize_precision", -1);
$this->load->helper('url');
$filePath = base_url('assets/zones/zone.geojson');
$jsonStream = JsonMachineJsonMachine::fromFile($filePath,"/features");
$this->PolygonModel->import($jsonStream)
}
// model
public function import ($jsonStream) {
$import = [];
foreach ($jsonStream as $name => $data) {
// $coordinates is nested indexed array with possibly thousands of elements
$coordinates = json_encode($data['geometry']['coordinates']);
$import['baz'][] = [
'foo' => 'bar',
'coordinates' => $coordinates
];
}
echo json_last_error_msg(); // gives no errors
// insert encoded data to db...
}
在从数据库选择字符串后，我使用这个代码来解码字符串
// decode and fix json if corrupted (huge arrays..)
private function decodeZoneCoords ($coordsJson) {
$decoded = json_decode($coordsJson, true);
if (!$decoded) {
// some fixes I've found online
$json = $coordsJson;
// before removing cntrl I get the"Control character error, possibly incorrectly encoded" error
$json = preg_replace('/[[:cntrl:]]/', '', $coordsJson);
$json = preg_replace('/[[:^print:]]/', '', $coordsJson);
$json = mb_convert_encoding($json,"UTF-8");
$json = ltrim($json . '"' ."]", '1');
if (0 === strpos(bin2hex($json), 'efbbbf')) {
$json = substr($json, 3);
}
$decoded = json_decode($json, true);
if (!$decoded) {
$json = rtrim($json, ',"]') . '"]';
$decoded = json_decode($json, true);
}
}
if (!$decoded) {
echo"<pre>";
var_dump( json_decode($json, true) ); // null
echo"</pre>";
echo json_last_error_msg(); //"syntax error"
echo 'JSON ERROR(from zone):';
echo '<hr>';
echo $json;
die();
}
return $decoded;
}
试图解码时，从json_last_error_msg函数中得到语法错误消息，json_encode函数返回null。
编辑：
我刚刚意识到var_dumping字符串给我这个：string(65535)。
即使我使用文本字段存储编码的字符串，MySql是否会截断JSON？