Table of Contents for

MySQL in a Nutshell, 2nd Edition

This function returns the field flags for a field of a results set given. See mysql_fetch_field() earlier in this chapter for a description of the flags. Specify the desired field through the offset in the second argument. Here is an example:

...
$sql_stmnt = "SELECT * FROM workreq LIMIT 1";
$results = mysql_query($sql_stmnt);
$num_fields = mysql_num_fields($results);
for ($index = 0; $index < $num_fields; $index++) {
  $field_name = mysql_field_name($results, $index);
  $flags = explode(' ', mysql_field_flags($results, $index));
  print "$field_name \n";
  print_r($flags);
  print "\n\n";
}
...

After retrieving one row as a sampler—using a for statement and the number of fields in the results set—this example determines the field name with mysql_field_name() and the flags for each field using mysql_field_flags(). The mysql_field_flags() function assembles the flags into an array in which the data is separated by spaces. By using the explode() PHP function, you can retrieve the elements of the array without having to know the number of elements, and they are stored in $flags. Next, print_r() displays the field name and prints out the flags. Here is the output of the script for the first field:

wrid
Array
(
    [0] => not_null
    [1] => primary_key
    [2] => auto_increment
)