如何根据我从客户端获得的JSON数组删除mysql记录？

Question

What I am doing in the code is basically getting all the ids currently in mysql database. Getting the ids from a JSON array. Comparing them and deleting the ids in the mysql table that are NOT in the JSON array.

<?php

Getting POST Data (Works)

       $test = $_POST["data"];
       $obj = json_decode($test, true);
       $data = $obj["myarray"];

First sql query (Works)

       $sql3 = "select id from pbs";
       $current_ids= mysqli_query($connection, $sql3)

initialize arrays for IDs (Works)

       $ids_array= array();
       $ids_array2= array();

Get current set of ids from mysql table and putting them in ids_array (Works)

       while($row = mysqli_fetch_array($current_ids)){
             $ids_array[] = $row['id'];
       }

Looping over each JSON array $data i.e [{$val}, {$val}, ...]

       foreach($data as $val){

This is one of the things I'm unsure about. Can I push each id value into and array? i.e:

if $val = {"id": "1", ...} $ids_array2 should have the value "1". If this is correct, I should have an array of new ids that I got from the JSON array.

            array_push($ids_array2, $val->id);

checks if row is in table by id. If it is, update the mysql row. If it is not, insert a new mysql row (Works)

            $check = mysqli_query($connection,"SELECT * FROM `pbs` WHERE `id`='".$val["id"]."'");

           if(mysqli_num_rows($check)==1){
                //Update the row

           }
           else{
                //Insert the row

           }
       }

For each item in $ids_array (current set of ids from mysql table). Delete it from table if it is not in $ids_array2 (newset of ids from JSON) where id = $item (Does not work)

      foreach($ids_array as $item){
           if(in_array($item, $ids_array2)==0){

                   $sql5 = "DELETE FROM pbs WHERE id='"$item"'";
                   $delete= mysqli_query($connection, $sql5);
               }    
       }

       mysqli_close($connection);

?> 

So what I am trying to do is INSERT, UPDATE and DELETE records depending on the JSON array I get from the client. Thanks!

Answer 1

You have syntax error in the query. This will work:

   foreach($ids_array as $item){
       if(!in_array($item, $ids_array2)){

               $sql5 = "DELETE FROM pbs WHERE id='".$item."'";
               $delete= mysqli_query($connection, $sql5);
           }    
   }

   mysqli_close($connection);

or use a single DELETE query:

   $deleteIds = [];
   foreach($ids_array as $item){
       if(!in_array($item, $ids_array2)){
           $deleteIds[] = $item;
       }    
   }

   $sql5 = "DELETE FROM pbs WHERE id IN (".implode(',', $deleteIds).")";
   $delete= mysqli_query($connection, $sql5);