Insert into table with multiple rows in subquery
<p>I want to have results in a table where the data comes from 3 different tables. </p>

<p>For that I have tried to execute this query:</p>

<pre><code>INSERT INTO sometable (id,date) 
VALUES 
   (
     (SELECT id FROM table1 
     UNION 
     SELECT id FROM table2 
     UNION 
     SELECT id FROM table3)
     ,
     (SELECT date FROM table1
     UNION 
     SELECT date FROM table2 
     UNION 
     SELECT date FROM table3)
  )
</code></pre>

<p>The result of this query is an error stating <code>cannot insert multiple rows</code>. Please help me to write this query correctly.  </p>