If you are thinking "What is a database?" or "Why MYSQL?", head on over to our MYSQL Tutorial. There you will not only learn the answer to these questions, you will also learn the basic commands needed to use MYSQL.
Once you are up to speed you can begin to learn how to integrate MYSQL commands directly into your PHP code.
PHP's MYSQLI class has over 60 built-in functions to meet your MYSQL interfacing needs. Just about anything that you ever wanted to do (and a few that you didn't) can be done with one function or another, but we will, in the next few pages, only concentrate on the fourteen functions that are most suited to our needs:
| Function | Description |
|---|---|
| mysqli_affected_rows() | Returns the number of affected rows in the previous MySQL operation |
| mysqli_close() | Closes a previously opened database connection |
| mysqli_connect() | Opens a new connection to the MySQL server |
| mysqli_errno() | Returns the last error code for the most recent function call |
| mysqli_error() | Returns the last error description for the most recent function call |
| mysqli_fetch_all() | Fetches all result rows as an associative array, a numeric array, or both |
| mysqli_fetch_array() | Fetches a result row as an associative, a numeric array, or both |
| mysqli_fetch_assoc() | Fetches a result row as an associative array |
| mysqli_fetch_row() | Fetches one row from a result-set and returns it as an enumerated array |
| mysqli_free_result() | Frees the memory associated with a result |
| mysqli_num_rows() | Returns the number of rows in a result set |
| mysqli_query() | Performs a query against the database |
| mysqli_real_escape_string() | Escapes special characters in a string for use in an SQL statement |
| mysqli_select_db() | Changes the default database for the connection |