code: func (h *ProxyQueryHandler) handlePostQuery(w http.ResponseWriter, r *http.Request) {
  	ctx := r.Context()
  
  	var req query.ProxyRequest
  	req.WithCompilerMappings(h.CompilerMappings)
  	req.WithDialectMappings(h.DialectMappings)
  	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
  		EncodeError(ctx, err, w)
  		return
  	}
  
  	hd, ok := req.Dialect.(HTTPDialect)
  	if !ok {
  		EncodeError(ctx, fmt.Errorf("unsupported dialect over HTTP %T", req.Dialect), w)
  		return
  	}
  	hd.SetHeaders(w)
  
  	n, err := h.ProxyQueryService.Query(ctx, w, &req)
  	if err != nil {
  		if n == 0 {
  			// Only record the error headers IFF nothing has been written to w.
  			EncodeError(ctx, err, w)
  			return
  		}
  		h.Logger.Info("Error writing response to client",
  			zap.String("handler", "transpilerde"),
  			zap.Error(err),
  		)
  	}
  }
docs: // handlePostQuery handles query requests.