Upload an asset in a custom form

Question

I am trying to upload/add an asset to an entry via a form on the website. The entry saves fine when I don't include the asset field but as soon as I add the asset field and try to upload a file I get this odd SQL error.

CDbCommand failed to execute the SQL statement: SQLSTATE[23000]: Integrity constraint violation: 1452 Cannot add or update a child row: a foreign key constraint fails (housewares.craft_relations, CONSTRAINT craft_relations_targetId_fk FOREIGN KEY (targetId) REFERENCES craft_elements (id) ON DELETE CASCADE).
The SQL statement executed was: INSERT INTO craft_relations (fieldId, sourceId, sourceLocale, targetId, sortOrder, dateCreated, dateUpdated, uid) VALUES (:row0_col0, :row0_col1, NULL, :row0_col3, :row0_col4, :row0_col5, :row0_col6, :row0_col7). Bound with :row0_col0='4', :row0_col1='27', :row0_col3='Golfclubs.jpg', :row0_col4=1, :row0_col5='2014-09-03 23:36:06', :row0_col6='2014-09-03 23:36:06', :row0_col7='a1e565e1-f6d3-4f3b-8a6f-2c049d236b13'

The field works fine in the CP.

This is the field

<input class="form-control" type="file" id="image" name="fields[image][]" />

Any ideas?

Answer 1

Problem solved! (head slap)

The <form> requires the following parameters:
enctype="multipart/form-data"

An odd error that gets thrown if omitted.