title: yii2. query with like condition
body: <p>In my yii2 application i need something like this:</p>
  
  <pre><code>SELECT * FROM customers WHERE first_name||' '||last_name ILIKE '%Nick%' ORDER BY "id";
  </code></pre>
  
  <p>This query gets customers with concatinated first_name and last_name like 'Nick'.</p>
  
  <p>In my yii1 application I can use CDBCriteria next way:</p>
  
  <pre><code>$criteria = new CDbCriteria;
          $criteria-&gt;addSearchCondition(
              "first_name||' '||last_name",
              'Nick',
              true,
              'and',
              'ILIKE'
          );
  
  $criteria-&gt;order = 't.id asc';
  </code></pre>
  
  <p>And this works fine.</p>
  
  <p>In yii2 I tried:</p>
  
  <pre><code>$a = \common\models\Customer::find()
          -&gt;filterWhere(['ILIKE', "first_name||' '||last_name", 'Nick'])
          -&gt;orderBy(['id' =&gt; SORT_ASC])
          -&gt;all();
  </code></pre>
  
  <p>And got exception column does not exist, and sql was:</p>
  
  <pre><code>SELECT * FROM "customers" WHERE "first_name||' '||last_name" ILIKE '%Nick%' ORDER BY "id"
  </code></pre>
  
  <p>Using \yii\db\Expression doesnt change situation.</p>