How to Fix the 'Commands Out of Sync' Error in PHP MySQL Queries?

Troubleshooting "Commands Out of Sync" Errors in PHP MySQL Queries

When working with PHP and MySQL, you might encounter the frustrating "Commands out of sync; you can't run this command now" error. This typically occurs when executing multiple MySQL queries consecutively without proper handling of their asynchronous nature. The core problem lies in the default unbuffered behavior of mysqli queries.

There are two effective solutions to address this:

1. Process the First Query's Results: Execute your initial query using $con->query(), and store the results in an array. Subsequent operations should then iterate through this array, ensuring each action is performed independently.

2. Employ Query Buffering: Utilize the store_result() method within your prepared statement. This forces mysqli to buffer the query results, preventing the "Commands out of sync" issue by avoiding on-demand row fetching.

Here's an example illustrating query buffering:

$countQuery = "SELECT ARTICLE_NO FROM AUCTIONS WHERE upper(ARTICLE_NAME) LIKE % ?%";
if ($numRecords = $con->prepare($countQuery)) {
    $numRecords->bind_param("s", $brand);
    $numRecords->execute();
    $numRecords->store_result(); // Buffer the results
    $data = $con->query($countQuery);
    $rowcount = $data->num_rows;
    // Proceed with your application logic
}

Remember that enabling query buffering can increase memory consumption when dealing with extensive datasets. Choose the method best suited to your data volume and application requirements.

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