title: Google Analytics API error "Selected dimensions and metrics cannot be queried together."
body: <p>I have to retrieve as many different metrics from my GA ecommerce as I can all at once. I'm using google api ruby client for that. And keep getting an error:</p>
  
  <pre><code>"message"=&gt;"Selected dimensions and metrics cannot be queried together." 
  </code></pre>
  
  <p>for example, for this request:</p>
  
  <pre><code>result = client.execute(api_method: api_method.data.ga.get, parameters: {
      'ids'        =&gt; 'ga:95561781',
      'start-date' =&gt; Date.new(2006,1,1).to_s,
      'end-date'   =&gt; Date.today.to_s,
      'dimensions' =&gt; 'ga:source,ga:medium,ga:country,ga:transactionId,ga:affiliation,ga:productSku,ga:productName',
      'metrics'    =&gt; 'ga:sessions,ga:transactionRevenue,ga:transactions,ga:uniquePurchases,ga:totalValue,ga:transactionTax'
  })
  </code></pre>
  
  <p>How do I know what request metrics and dimensions I can combine and what not? And how can I retrieve as many data as I can?</p>