Witch spell list by school

[Rickshaw]

I'm attempting to figure out which school to take in spell focus (and variation tattoo, bloodmage initiate, and greater spell focus) for a debuffing witch. So far I'm thinking necromancy, or possibly conjuration, but I'm having a hard time pawing through all the spells on the pfsrd and getting a good idea of what spell is in what school.

Is there any tool that lists witch spells by school out there?

[Roxxy]

Witches don't have spell schools. That's a Sor/Wiz thing. That's why only they have spells listed by schools.

[Psyren]

The above is not quite correct - while it's true that only the sor/wiz spell list is broken out by school, all spell lists still do have schools, even clerics and bards etc. In other words, Witches can benefit from Spell Focus just like Wizards can. The difference is merely that only Wizards can ban/specialize in schools, so that breakout is more important for players to see at a higher level so that they don't have to flip to every individual spell to see if it is on their restricted list or not.

And yes, it's quite possible to view all Witch spells of X school. You'll simply need a database, like the PFSRD's advanced spell search (http://www.d20pfsrd.com/magic/tools/advanced-spell-search), or spreadsheets of all the Pathfinder spells (http://www.pathfindercommunity.net/home/databases/spells) which you can download and apply complex filtering in your spreadsheet program of choice. This will let you display complex results, such as "all Witch spells of the Necromancy school of 5th level or lower that have a saving throw."

[Gracht Grabmaw]

If you want to go full "Gods against thee and thine forever" (disfiguring people, shrinking people, poisoned gifts, the whole deal) witch I recommend transmutation. If you want something more strictly combat oriented pick necromancy.

[Psyren]

Enchantment is a fine choice too thanks to Coaxing Spell and Threnodic Spell. Be TN and you can bypass most immunities.

The one big problem with enchantment though is that for most things that are vulnerable, you're better off just using your Slumber Hex.

Conjuration is a fine choice so that you can pick up Augment Summoning; witches make halfway decent summoners, particularly if you buff your summons with Fortune and Ward (which you can do all day long.)