# Inputs

<p>This guide introduces you to the concept of inputs in Profiles and shows how to use them in your Profiles project.</p>
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<h2 id="overview">Overview</h2><p>The foundation of every companies data is the source files and data tables - these are the inputs that go into every data product a company produces.</p>
<p>In Profiles, <code>inputs</code> contain the IDs for identity graphs and the fields that build into a Customer360 (C360). They can be database tables or views, S3 buckets, and/or CSV files.</p>
<p><strong>SQL Keyword</strong>: <code>FROM</code></p>
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<h2 id="usage">Usage</h2><p>You can define <code>inputs</code> in the <a href="https://www.rudderstack.com/docs/profiles/dev-docs/inputs-yaml/" ><code>inputs.yaml</code></a> file, as shown:</p>
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  <div class="highlight"><pre class="chroma"><code class="language-yaml" data-lang="yaml">inputs:
  - name: rsIdentifies
    app_defaults:
      table: autotrack_data.autotrack.identifies
      occurred_at_col: timestamp
      ids:
        - select: &#34;user_id&#34;
          type: user_id
          entity: user
        - select: &#34;anonymous_id&#34;
          type: anonymous_id
          entity: user
        - select: &#34;lower(email)&#34;
          type: email
          entity: user
  - name: rsPages
    app_defaults:
      table: autotrack_data.autotrack.pages
      occurred_at_col: timestamp
      ids:
        - select: &#34;user_id&#34;
          type: user_id
          entity: user
        - select: &#34;anonymous_id&#34;
          type: anonymous_id
          entity: user</code></pre></div>
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<h2 id="best-practices">Best practices</h2><ul>
<li>Though it is possible to bring in data sources that only have one identifier column for your entity, it is best to have two or more columns, especially for <code>inputs</code> that you want to use as a source for the <code>id_stitcher</code> model.</li>
<li>If any of your ID columns are not of the string data type, then you must case them explicitly, as shown below:</li>
</ul>
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  <div class="highlight"><pre class="chroma"><code class="language-yaml" data-lang="yaml">      ids:
        - select: &#34;CAST(user_id AS VARCHAR)&#34;
          type: user_id
          entity: user</code></pre></div>
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