We study Choquard type equation of the form where Nge 3, I_alpha is the Riesz potential with alpha in (0,N), p>1, q>2 and varepsilon ge 0. Equations of this type describe collective behaviour of self-interacting many-body systems. The nonlocal nonlinear term represents long-range attraction while the local nonlinear term represents short-range repulsion. In the first part of the paper for a nearly optimal range of parameters we prove the existence and study regularity and qualitative properties of positive groundstates of (P_0) and of (P_varepsilon ) with varepsilon >0. We also study the existence of a compactly supported groundstate for an integral Thomas–Fermi type equation associated to (P_{varepsilon }). In the second part of the paper, for varepsilon rightarrow 0 we identify six different asymptotic regimes and provide a characterisation of the limit profiles of the groundstates of (P_varepsilon ) in each of the regimes. We also outline three different asymptotic regimes in the case varepsilon rightarrow infty . In one of the asymptotic regimes positive groundstates of (P_varepsilon ) converge to a compactly supported Thomas–Fermi limit profile. This is a new and purely nonlocal phenomenon that can not be observed in the local prototype case of (P_varepsilon ) with alpha =0. In particular, this provides a justification for the Thomas–Fermi approximation in astrophysical models of self-gravitating Bose–Einstein condensate.