(PHP 5, PECL OCI8 >= 1.1.0)
oci_field_precision — Tell the precision of a field
$statement
   , int $field
   )
   Returns precision of the field.
  
For FLOAT columns, precision is nonzero and scale is -127. If precision is 0, then column is NUMBER. Else it's NUMBER(precision, scale).
statementA valid OCI statement identifier.
fieldCan be the field's index (1-based) or name.
   Returns the precision as an integer, or FALSE on errors.
  
Note:
In PHP versions before 5.0.0 you must use ocicolumnprecision() instead. This name still can be used, it was left as alias of oci_field_precision() for downwards compatability. This, however, is deprecated and not recommended.