spark-instrumented-optimizer/docs/sql-ref-syntax-qry-select-orderby.md

---
layout: global
title: ORDER BY Clause
displayTitle: ORDER BY Clause
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  this work for additional information regarding copyright ownership.
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---
The <code>ORDER BY</code> clause is used to return the result rows in a sorted manner
in the user specified order. Unlike the [SORT BY](sql-ref-syntax-qry-select-sortby.html)
clause, this clause guarantees a total order in the output.

### Syntax
{% highlight sql %}
ORDER BY { expression [ sort_direction | nulls_sort_oder ] [ , ... ] }
{% endhighlight %}

### Parameters
<dl>
  <dt><code><em>ORDER BY</em></code></dt>
  <dd>
    Specifies a comma-separated list of expressions along with optional parameters <code>sort_direction</code>
    and <code>nulls_sort_order</code> which are used to sort the rows.
  </dd>
  <dt><code><em>sort_direction</em></code></dt>
  <dd>
    Optionally specifies whether to sort the rows in ascending or descending
    order. The valid values for the sort direction are <code>ASC</code> for ascending
    and <code>DESC</code> for descending. If sort direction is not explicitly specified, then by default
    rows are sorted ascending. <br><br>
    <b>Syntax:</b>
    <code>
       [ ASC | DESC ]
    </code>
  </dd>
  <dt><code><em>nulls_sort_order</em></code></dt>
  <dd>
    Optionally specifies whether NULL values are returned before/after non-NULL values. If
    <code>null_sort_order</code> is not specified, then NULLs sort first if sort order is
    <code>ASC</code> and NULLS sort last if sort order is <code>DESC</code>.<br><br>
    <ol>
      <li> If <code>NULLS FIRST</code> is specified, then NULL values are returned first
           regardless of the sort order.</li>
      <li>If <code>NULLS LAST</code> is specified, then NULL values are returned last regardless of
           the sort order. </li>
    </ol><br>
    <b>Syntax:</b>
    <code>
       [ NULLS { FIRST | LAST } ]
    </code>
  </dd>
</dl>

### Examples
{% highlight sql %}
CREATE TABLE person (id INT, name STRING, age INT);
INSERT INTO person VALUES
    (100, 'John', 30),
    (200, 'Mary', NULL),
    (300, 'Mike', 80),
    (400, 'Jerry', NULL),
    (500, 'Dan',  50);

-- Sort rows by age. By default rows are sorted in ascending manner with NULL FIRST.
SELECT name, age FROM person ORDER BY age;

  +-----+----+
  |name |age |
  +-----+----+
  |Jerry|null|
  |Mary |null|
  |John |30  |
  |Dan  |50  |
  |Mike |80  |
  +-----+----+

-- Sort rows in ascending manner keeping null values to be last.
SELECT name, age FROM person ORDER BY age NULLS LAST;

  +-----+----+
  |name |age |
  +-----+----+
  |John |30  |
  |Dan  |50  |
  |Mike |80  |
  |Mary |null|
  |Jerry|null|
  +-----+----+

-- Sort rows by age in descending manner, which defaults to NULL LAST.
SELECT name, age FROM person ORDER BY age DESC;

  +-----+----+
  |name |age |
  +-----+----+
  |Mike |80  |
  |Dan  |50  |
  |John |30  |
  |Jerry|null|
  |Mary |null|
  +-----+----+

-- Sort rows in ascending manner keeping null values to be first.
SELECT name, age FROM person ORDER BY age DESC NULLS FIRST;

  +-----+----+
  |name |age |
  +-----+----+
  |Jerry|null|
  |Mary |null|
  |Mike |80  |
  |Dan  |50  |
  |John |30  |
  +-----+----+

-- Sort rows based on more than one column with each column having different
-- sort direction.
SELECT * FROM person ORDER BY name ASC, age DESC;

  +---+-----+----+
  |id |name |age |
  +---+-----+----+
  |500|Dan  |50  |
  |400|Jerry|null|
  |100|John |30  |
  |200|Mary |null|
  |300|Mike |80  |
  +---+-----+----+
{% endhighlight %}

### Related Clauses
- [SELECT Main](sql-ref-syntax-qry-select.html)
- [WHERE Clause](sql-ref-syntax-qry-select-where.html)
- [GROUP BY Clause](sql-ref-syntax-qry-select-groupby.html)
- [HAVING Clause](sql-ref-syntax-qry-select-having.html)
- [SORT BY Clause](sql-ref-syntax-qry-select-sortby.html)
- [CLUSTER BY Clause](sql-ref-syntax-qry-select-clusterby.html)
- [DISTRIBUTE BY Clause](sql-ref-syntax-qry-select-distribute-by.html)
- [LIMIT Clause](sql-ref-syntax-qry-select-limit.html)