site/docs/3.5.0/generated-conditional-funcs-table.html

<table class="table">
  <thead>
    <tr>
      <th style="width:25%">Function</th>
      <th>Description</th>
    </tr>
  </thead>
  <tbody>
    <tr>
      <td>coalesce(expr1, expr2, ...)</td>
      <td>Returns the first non-null argument if exists. Otherwise, null.</td>
    </tr>
    <tr>
      <td>if(expr1, expr2, expr3)</td>
      <td>If `expr1` evaluates to true, then returns `expr2`; otherwise returns `expr3`.</td>
    </tr>
    <tr>
      <td>ifnull(expr1, expr2)</td>
      <td>Returns `expr2` if `expr1` is null, or `expr1` otherwise.</td>
    </tr>
    <tr>
      <td>nanvl(expr1, expr2)</td>
      <td>Returns `expr1` if it's not NaN, or `expr2` otherwise.</td>
    </tr>
    <tr>
      <td>nullif(expr1, expr2)</td>
      <td>Returns null if `expr1` equals to `expr2`, or `expr1` otherwise.</td>
    </tr>
    <tr>
      <td>nvl(expr1, expr2)</td>
      <td>Returns `expr2` if `expr1` is null, or `expr1` otherwise.</td>
    </tr>
    <tr>
      <td>nvl2(expr1, expr2, expr3)</td>
      <td>Returns `expr2` if `expr1` is not null, or `expr3` otherwise.</td>
    </tr>
    <tr>
      <td>CASE WHEN expr1 THEN expr2 [WHEN expr3 THEN expr4]* [ELSE expr5] END</td>
      <td>When `expr1` = true, returns `expr2`; else when `expr3` = true, returns `expr4`; else returns `expr5`.</td>
    </tr>
  </tbody>
</table>