Ok..
I have this field on the database
CREATE TABLE opiv1 (
  idopinion INTEGER(10) UNSIGNED NOT NULL,
   comntario LONGTEXT NULL,
   PRIMARY KEY(idopinion)
);

when I apply a select function, I need the field name...
I use mysql_field_type on the data collect.

$numcampos=mysql_num_fields($result);
for ($i=0;$i<$numcampos;$i++){
 $cab=mysql_field_name($result,$i);
 echo "Field $i: $cab";
}

he most to write:

Field Int
Field LongText

and this show me

Field Int
Field Blob

We need more than this to begin handling this bug. Please tell us what MySQL version you are using, and give us a code snippet that matches your output.

$cab=mysql_field_name($result,$i);
echo "Field $i: $cab";
This wouldn't output "Field Int".

A working, minimal example would be beneficial in addition to your MySQL version.

Your sample is wrong: mysql_field_name returns the name of 
the field, not the type. 
 
Also the mysql_field functions return resultset metadata 
information, and not database metadata information. If you 
need to retrieve the defined columntype use MySQL's SQL 
functions for. 

georg@php.net you are WRONG!!!!!

for ($i=0;$i<$numcampos;$i++){
 $cab=mysql_field_name($result,$i); // I use a right function
 echo "Field $i: $cab";
}

I work with mysql 4.0