foreq循环中的Mysqli_query

Question

I'm having trouble with a mysqli_query from inside a foreach loop, I'm getting a string from a table first, then separating that into an array. Then I try looping through the array and calling a query inside the loop.

$langs_result = mysqli_query($con, "SELECT Languages FROM users WHERE Username = '$username'");

    $row = mysqli_fetch_assoc($langs_result);

    $langs = $row['Languages'];
    $userLangs = str_replace(" ","",$langs);
    $userLangs = explode(",",$langs);
    print_r($userLangs);
    $posts = array();

    foreach($userLangs as $lang){
        echo "$lang <br>";
        $sql = "SELECT * FROM posts WHERE Language = '$lang'";
        $getLangPosts = mysqli_query($con, $sql);
        array_push($posts, mysqli_fetch_assoc($getLangPosts));
    }

    print_r($posts);

for this user the langusges are German, Italian, Danish, and English, but the $posts array only contains the first post found from the first language (German), can anybody help? I am trying to get all of the posts for each language in the $userLangs array.

It's going through the foreach loop okay as the $lang variable that's echoed changes each time but the query still isn't working properly.

Thanks for the help!

Answer 1

UPDATE
See this code:

<?php

$langs_result = mysqli_query($con, "SELECT Languages FROM users WHERE Username = '$username'");

$row = mysqli_fetch_assoc($langs_result);

$langs = $row['Languages'];

// $langs = 'German, Italian, Danish, French'; added this to run the test

// $userLangs = str_replace(" ","",$langs); this is not needed, see the explode below
$userLangs = explode(", ",$langs);

foreach($userLangs as $lang){
    echo $lang;
    $sql = "SELECT * FROM posts WHERE Language = '$lang'";

    $getLangPosts = mysqli_query($con, $sql); // this is the result of the select *
    while($post = mysqli_fetch_assoc($getLangPosts)){ // iterate over all the results
        $postField = $post["yourChoiceField..say..Title"]; // get something from each row
        array_push($posts, $title); // push into array
    }
}

print_r($posts);

Since the initial select is based on username I don't believe the first loop is needed so your code was on the right track.
A second loop was needed to iterate over the posts though and a field to populate the $posts array.

---

You need to perform mysqli_fetch_assoc in a loop

$langs_result = mysqli_query($con, "SELECT Languages FROM users WHERE Username = '$username'");

while($row = mysqli_fetch_assoc($langs_result)){

    $langs = $row['Languages'];

    $userLangs = str_replace(" ","",$langs); // i don't get why you are doing this though
    $userLangs = explode(",",$langs);
    print_r($userLangs);

    $posts = array();

    foreach($userLangs as $lang){
        echo "$lang <br>";
        $sql = "SELECT * FROM posts WHERE Language = '$lang'";
        $getLangPosts = mysqli_query($con, $sql);
        array_push($posts, mysqli_fetch_assoc($getLangPosts));
    }

    print_r($posts);
}

It would help to know how what the select query actually returns.