Search results for: "invalid result resources"

What are some common pitfalls when using SQL left join in PHP?

One common pitfall when using SQL left join in PHP is forgetting to check for null values in the result set, which can lead to unexpected behavior or...

What are common pitfalls when sending emails using PHP mail function?

One common pitfall when sending emails using the PHP mail function is not properly setting the headers, which can result in emails being marked as spa...

What are some common errors that can occur when including PHP functions in HTML files and how can they be resolved?

One common error when including PHP functions in HTML files is forgetting to enclose the PHP code within `<?php ?>` tags. This can result in the PHP c...

What are the potential pitfalls of having output before the session_start() function in PHP?

Having output before the session_start() function in PHP can lead to headers already being sent, which will result in an error message like "Cannot se...

What are the drawbacks of using SELECT * in SQL queries, as highlighted in the forum discussion?

Using SELECT * in SQL queries can lead to performance issues because it retrieves all columns from the table, even if they are not needed. This can re...