title: SQL: Removing rows based on a condition
body: <p>I need to remove the values of columns which is easily doable with for loops and if conditions. However, I don't know how to do in SQL. The table that I have looks like the following</p>
  <pre><code>dt   _______ level ________ cohort_size ________ daily_users
  2020 _______ D5    ________ 345.        ________ 12
  2020 _______ D3    ________ 32          ________ 32
  2019 _______ D0    ________ 78.         ________ 78 
  2019 _______ D4.   ________ 67          ________ 56
  2018 _______ D0    ________ 56          ________ 9
  </code></pre>
  <p>What I am trying to do is to remove the rows where the level is D0 and the cohort_size = daily active users. So basically I should only remove row 3. Everything else remains the same. Do you have any suggestions on how to proceed this?</p>
  <p>Thank you.</p>