This a FAQ (Frequentyl Asked Question) which has been asked and answered multiple times and can be also solved by reading the documentation:
Returns FALSE on failure. For successful SELECT, SHOW, DESCRIBE or EXPLAIN queries mysqli_query() will return a mysqli_result object. For other successful queries mysqli_query() will return TRUE.
You have to check the return value of
as shown in the examples at the above link before passing it to other functions like
Upon failures report the error message to know what went wrong. Usual errors sources are invalid SQL commands and the message provided by
will tell you what was wrong. Because I don't know about your database, I can only guess. Here it might be a typo in one of the column names or the table name.