select by joining tables with the where clause

[sem_db]

I would like to join all the tables in my database in a SELECT clause, but this table linking is extremely slow. Why is the following select statement so slow?????
See attached ER diagram

SELECT distinct Medias.pk_media_id, Organisms.common_name, Tissues.type As tiss_type, Cells.type As cell_type,
Organelles.type As org_type, Macromolecules.type As macro_type, Authors.last_name, Authors.organization, Medias.file_name, Medias.format, Medias.label

FROM Medias, Organisms, MediaAuthors, MediaTissues, MediaCells, MediaOrganelles, MediaMacromolecules, Authors, Techniques, Tissues, Cells, Organelles, Macromolecules, Admin

WHERE Macromolecules.pk_macromolecule_id = 1 and Medias.fk_organism_id = Organisms.pk_organism_id and Medias.fk_technique_id = Techniques.pk_technique_id
and Medias.pk_media_id = MediaAuthors.fk_media_id and MediaAuthors.fk_author_id = Authors.pk_author_id
and Medias.pk_media_id = MediaTissues.fk_media_id and MediaTissues.fk_tissue_id = Tissues.pk_tissue_id
and Medias.pk_media_id = MediaCells.fk_media_id and MediaCells.fk_cell_id = Cells.pk_cell_id
and Medias.pk_media_id = MediaOrganelles.fk_media_id and MediaOrganelles.fk_organelle_id = Organelles.pk_organelle_id
and Medias.pk_media_id = MediaMacromolecules.fk_media_id and MediaMacromolecules.fk_macromolecule_id =
Macromolecules.pk_macromolecule_id and Medias.fk_admin_id = Admin.pk_admin_id

[nemonoman]

Try to avoid "distinct". In such a query, it would definitely slow things down.

You could also try this

$myquery ="EXPLAIN SELECT distinct Medias.pk_media_id, Organisms.common_name, Tissues.type As tiss_type, Cells.type As cell_type...."

etc.

then run the query and get the results.

See the EXPLAIN section

http://www.mysql.com/doc/en/EXPLAIN.html

Interpreting EXPLAINs is a lot like necromancy, IMO, some people really have a talent for it. I don't.

If this was my problem, I'd get the EXPLAIN and post it and beg for someone to tell me what it all means...