I'm used to playing Oracle for a necromancer, I like charisma characters and the fact they get more spell slots. Also my most recent GM allowed for the original Juju mystery and the Agent of the Grave prestige class. But I've been looking at the Devout Pilgrim and Idealist Cleric and the ability to cast Inflict Wounds at 30ft if I spend just one minute in prayer with my minions seems very appealing, also it seems Invoke Realm can be used for Desecrate? I'm not used to playing cleric so I don't know if I'm misunderstading. Suming it up I want to know if it's worth giving a try to cleric or if I should stick to Oracle.
Not sure if this answers your question, but I played a Cleric necromancer build a while back.
I played a Neutral Separatist Cleric, and took the Versatile Channeling feat. It was really neat to be able to channel to heal my party, or heal my undead, or to damage the enemy.
Be sure to read this article about your Undead buckets, it will help you know just how many undead you can drag around. It's written for Clerics in mind, but quite a bit will still apply.
https://docs.google.com/file/d/0B5kvBvq2DEHjRWFhSWc1ZzAzaDg/edit?resourceke y=0-14szXwlKO7ndjgv4Q3A9EQ
Both the cleric and oracle make excellent necromancers. If you are used to a spontaneous caster playing a prepared caster is a very different play style. Getting access to your entire spell list can be a huge advantage, but having to choose your spells in advance can be a challenging. You have to be constantly evaluating what you are likely to need, and a mistake can really render the character useless. On the other hand, if you do have accurate information you can prepare for just about anything. The good news is that as long as you survive you can adjust the next day.
The other thing is that clerics get very few class features other than spell. You have channel energy and your domain powers, but that is about it.