Philip Dayer, a non-executive director at Aveva, spent £14,901 buying shares at the company as a sign of confidence in the company following recent concerns about how the oil price will affect the business.Dayer bought 1,134 shares at a price of 1,314p each and now holds 7,696 shares in the engineering software group.Aveva has seen its share price fall sharply recently on the back of the collapse in oil prices.On Thursday, the group's share price came under further pressure after Morgan Stanley and JPMorgan Cazenove downgraded the stock to 'underweight'.Last month, Aveva reported "disappointing" half-year results with a 21% decrease in revenues and 48% in pre-tax profits.Chief executive Richard Longdon said at the time of the report that the board expects to "experience tougher trading conditions in Russia as sanctions begin to impact the energy industry" and "uncertainty over the oil price is likely to affect near term oil & gas capital expenditure spending decisions".In a more positive note, Longdon said: "Despite the challenges encountered in the first half, the board remains confident of Aveva's future. We expect to achieve a result in line with the Board's current expectations for the current fiscal year."Top Director BuysEG Solutions (EGS) Director name: Mr Duncan J McIntyreAmount purchased: 127,389 @ 65.00p Value: £82,803Landore Resources Ltd. (LND) Director name: Mr William HumphriesAmount purchased: 1,754,119 @ 1.68p Value: £29,469Aveva Group (AVV) Director name: Mr Philip John DayerAmount purchased: 1,134 @ 1,314.00p Value: £14,901Top Director SellsRockhopper Exploration (RKH) Director name: Mr Samuel John MoodyAmount sold: 237,136 @ 60.25p Value: £142,874Cobham (COB) Director name: Mr Robert (Bob) Murphy Amount sold: 34,051 @ 314.82p Value: £107,199CSR (CSR) Director name: Dr Levy GerzbergAmount sold: 2,946 @ 838.72p Value: £24,709CSR (CSR) Director name: Dr Levy GerzbergAmount sold: 2,454 @ 840.40p Value: £20,623