Changing to isset
Adding unit test.
Fixing problem with Postgresql adapters. BIGINT was begin converted to float. Other adapters were not doing this, and this was not necessary, since PHP will work fine on 64-bit machines, and on 32-bit machine will convert to float. We do NOT want to second-guess PHP here. Floats and integers do not compare equally, and it will cause problems if we always return float.
Merge pull request #311 from spekary/feature-DbSpeedImprovement

Feature db speed improvement