I have been self-teaching myself some open source GIS.
I downloaded QGIS and have been following this four part tutorial - http://www.youtube.com/watch?v=XUD6zcNGl4A&list=UUZkLX9x-HiA4B0sGPPvZMcQ. That's part 3, where at 5:21 he filters attribute table for NULL under the OPERATOR column. I don't have his search bar, but I can filter columns. I can choose OPERATOR and type in NULL (or null, case sensitive doesn't matter). It'll filter out to ~5000 results from ~12000 oil wells. However, I cannot save this as a new layer. If I have editing toggled "Save for selected layer(s)" is grayed out. When I click on "save as" the "Save only for selected features box" is also grayed out, and cannot be selected. Any help with this?
Also sometimes, if I do just save as a new layer it will save every well (all ~12000) as the new layer.
I'm using QGIS 2.4.0 on Windows 7.