<h2 id="heading-context">Context</h2>
<p>You have a column in your table that is used as an  <a target="_blank" href="https://guides.rubyonrails.org/active_record_postgresql.html#array">array</a> , like this: </p>
<pre><code class="lang-ruby"> t.string <span class="hljs-string">'ids'</span>, <span class="hljs-symbol">array:</span> <span class="hljs-literal">true</span>
</code></pre>
<p>And you want to select all records that have more than N elements in the array</p>
<h2 id="heading-solution">Solution</h2>
<p>In PostgreSQL, you can use  <a target="_blank" href="https://www.postgresql.org/docs/current/functions-array.html"><code>cardinality</code></a>  to achieve this:</p>
<pre><code>Model.where(<span class="hljs-string">"cardinality(ids) &gt; 5"</span>)
</code></pre>

## Context

You have a column in your table that is used as an  [array](https://guides.rubyonrails.org/active_record_postgresql.html#array) , like this: 

```ruby
 t.string 'ids', array: true
```

And you want to select all records that have more than N elements in the array

## Solution

In PostgreSQL, you can use  [`cardinality`](https://www.postgresql.org/docs/current/functions-array.html)  to achieve this:

```
Model.where("cardinality(ids) > 5")
```









Active Record: How to select rows based on the number of items in an array column (PostgreSQL)

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Active Record: How to select rows based on the number of items in an array column (PostgreSQL)

Context

Solution