title: Sequelize | Return results if either hasMany association matches their where conditions
body: <p>I have model <strong>A</strong>, <strong>B</strong>, and <strong>C</strong>.</p>
  
  <p><strong>A</strong> has a hasMany association to <strong>B</strong> &amp; <strong>C</strong> ( and <strong>B</strong> &amp; <strong>C</strong> have a belongsTo association back to <strong>A</strong> )</p>
  
  <p>I want to return records of <strong>A where B.b_column = 'b' OR C.c_column = 'c'</strong>.  </p>
  
  <p>My current approach was to trying using the <strong><em>required: false</em></strong> in the where's but that just returns all the records of A and the associations IF they exist.  I also tried using <strong><em>separate: true</em></strong> on the associations, but it still seemed to be bringing back more records than I want.</p>
  
  <pre><code>var results = await A.all({
        include: [
          { 
            model: B, as: "Bs",
            where: { b_column: "b"},
            separate: true
          },
          { 
            model: C, as: "Cs",
            where: {c_column: "c"},
            separate: true
          },
        ]
      });
  </code></pre>