What does the error message "Commands out of sync; you can't run this command now" indicate when executing MySQL queries in PHP?

The error message "Commands out of sync; you can't run this command now" in MySQL queries in PHP indicates that multiple queries are being executed on the same database connection without fetching the results. To solve this issue, you need to make sure to fetch all the results from the previous query before executing the next one.

// Execute the first query
$result1 = mysqli_query($conn, "SELECT * FROM table1");

// Fetch all the results from the first query
while ($row = mysqli_fetch_assoc($result1)) {
    // Process the results
}

// Execute the second query
$result2 = mysqli_query($conn, "SELECT * FROM table2");

// Fetch all the results from the second query
while ($row = mysqli_fetch_assoc($result2)) {
    // Process the results
}