Like when digging a tunnel it might be helpful to troubleshoot this issue from two ways. Or maybe from multiple ends.

**From the Tridion CD side**

If you publish a SmartTarget enabled DCP and the publishing process is succesfull the SmartTarget deployer has deployed the DCP to Fredhopper and the DCP is processed in the Fredhopper indexer instance. Are you sure that the SmartTarget deployer is installed and conifgured in the cd_deployer_conf.xml for the target you are publishing to?

The Content Delivery web service (aka SmartTarget web service or OData service) takes the Fredhopper URL from the smarttarget_conf.xml. Check the URL and Authencication settings in the QueryServer section.

**From the Fredhopper side**

The SmartTarget promotions (and DCPs IIRC) are hidden in the Fredhopper business manager, this is a feature of the SmartTarget API extension for Fredhopper. This might explain why you cannot see the DCPs in Fredhopper, did you disable This? Check [Hiding and showing Promotions in Business Manager][1] (login required) in the documentation (login required).

You mentioned there is this database error in the qserver log and the Promotions overview. If you can browse the Fredhopper Business Manager you should be able to view promotions in http://the.fredhopper.host:8180/fredhopper/admin/campaigns.fh?

  [1]: http://sdllivecontent.sdl.com/LiveContent/content/en-US/SDL_SmartTarget_2014-v1/GUID-287608E8-1E7A-4BE5-9682-B84B8FB4B8E4