如何从表中获取具有数组确切ID的产品？

Question

I have a sql table with products and i don't get how to retrieve several products using array with their ids

i know how retrieve all of these products and only one using id

JSON with all products from sql

function loadGoods(){
    $conn = connect(); 
    $sql = "SELECT * FROM PRODUCTS";
    $result = mysqli_query($conn, $sql);

    if (mysqli_num_rows($result) > 0) {
        $out = array();
        // output data of each row
        while($row = mysqli_fetch_assoc($result)) {
            $out[$row["id"]] = $row;
        }
        echo json_encode($out);

    } else {
        echo 0;
    }
    mysqli_close($conn);
}

JSON with one product using its id received in js file from hash

function loadSingleGoods(){
    $id = $_POST['id'];
    $conn = connect(); 
    $sql = "SELECT * FROM PRODUCTS WHERE id='$id'";
    $result = mysqli_query($conn, $sql);

    if (mysqli_num_rows($result) > 0) {
        $row = mysqli_fetch_assoc($result);
        echo json_encode($row);

    } else {
        echo 0;
    }
}

Both of these snippets are working and now i have array with id's but i don't get how retrieve only their properties from sql in JSON file.

I have array with ids like this ["6", "7", "27"] and i need to retrieve from sql PRODUCTS only items with these ids. As i understand i have to do something with this line

 $sql = "SELECT * FROM PRODUCTS WHERE id='$id'"; 

i tried such code

 $sql = "SELECT * FROM PRODUCTS WHERE in_array("id", $ids, TRUE); 

but it didn't work

Answer 1

It would be helpful if you showed us your JavaScript also, but assuming you're feeding the output of the json_encode() into a single variable, you can access each product like so:

console.log(json_variable[0]);

That should give you the first "row". To access a particular cell, try this:

console.log(json_variable[0]['column_name']);

To go thru all of them, try jQuery's each() :

$.each( json_variable, function( id, column_name) {
  console.log( id + ": " + column_name);
});

Answer 2

You can parse json object using JSON.parse() and access all the value of the object.

var text = '{ "name":"John", "age":"39", "city":"New York"}';
JSON.parse(text, function (key, value) {  
    console.log(value); 
});

Here you can replace text with your json variable.

If you want to read more about json parse & how to access json variable in js click here .

Answer 3

You can build your query before executing it:

 $sql_array=array("6", "7", "27");
 $first_item=array_values($sql_array)[0];
 $sql="SELECT * FROM `PRODUCTS` WHERE `id`='$first_item'";
 $built_query="";
 foreach ($sql_array as $k => $id) {
   if ($k < 1) continue;
   $built_query=$built_query." OR `id` = '$id'";
}
$built_query=$sql.$built_query;

echo "$built_query";