PHP警告：mysqli :: real_escape_string（）期望参数1为字符串，给定数组

I'm getting a warning from PHP:

PHP Warning: mysqli::real_escape_string() expects parameter 1 to be string, array given in ..

The code giving the warning is:

$saveData = array_map(array($connection, 'real_escape_string'), $saveData);

$saveData is decoded JSON taken from $_POST - typical dataset would be:

array(22) {
  ["quoteID"]=>
  string(7) "GLY0YQ5"
  ["Inventory"]=>
  array(0) {
  }
  ["pickupLocation"]=>
  string(15) "EPPING NSW 2121"
  ["dropOffLocation"]=>
  string(17) "RICHMOND VIC 3121"
  ["pickupSuburb"]=>
  string(6) "EPPING"
  ["pickupPostcode"]=>
  string(4) "2121"
  ["pickupState"]=>
  string(3) "NSW"
  ["dropoffSuburb"]=>
  string(8) "RICHMOND"
  ["dropoffPostcode"]=>
  string(4) "3121"
  ["dropoffState"]=>
  string(3) "VIC"
  ["pickupLatitude"]=>
  string(10) "-33.772549"
  ["pickupLongitude"]=>
  string(10) "151.082365"
  ["dropoffLatitude"]=>
  string(10) "-37.818587"
  ["dropoffLongitude"]=>
  string(10) "144.999181"
  ["pickupDistance"]=>
  string(1) "0"
  ["pickupAccess"]=>
  string(1) "0"
  ["dropoffDistance"]=>
  string(1) "0"
  ["dropoffAccess"]=>
  string(1) "0"
  ["regionalLoading"]=>
  string(1) "0"
  ["totalVolume"]=>
  string(2) "39"
  ["totalDistance"]=>
  string(3) "897"
  ["totalPrice"]=>
  string(4) "3120"
}

My understanding is the issue is mysqli expecting the first parameter to be the $connection variable, which it actually is, it's just different to the regular mysqli format because of the format required by array_map.

Given the outcome desired is the real_escape the entire array in one shot, and that the error is just a warning and is actually working, is there a better way to do this, and is it even necessary to make an adjustment?

["Inventory"]=>
  array(0) {
  }

Your problem is that your data contains an array, which cannot be escaped by mysqli::real_escape_string and which is triggering the warning. Make sure all values in the array are scalar values, not complex values like arrays, before attempting to escape them.