huaxingao commented on a change in pull request #27290: [SPARK-30583][DOC]
Document LIMIT Clause of SELECT statement in SQL Reference
URL: https://github.com/apache/spark/pull/27290#discussion_r368803034
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File path: docs/sql-ref-syntax-qry-select-limit.md
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@@ -18,5 +18,71 @@ license: |
See the License for the specific language governing permissions and
limitations under the License.
---
+The <code>LIMIT</code> clause is used to constrain the number of rows returned
by the <code>SELECT</code> statement.
+In general, this clause is used in conjuction with <code>ORDER BY</code> to
ensure that the results are deterministic.
-**This page is under construction**
+### Syntax
+{% highlight sql %}
+LIMIT { ALL | integer_expression }
+{% endhighlight %}
+
+### Parameters
+<dl>
+ <dt><code><em>ALL</em></code></dt>
+ <dd>
+ If specified, the query returns all the rows. In other words, no limit is
applied if this
+ option is specified.
+ </dd>
+ <dt><code><em>integer_expression</em></code></dt>
+ <dd>
+ Specifies an expression that returns an integer.
+ </dd>
+</dl>
+
+### Examples
+{% highlight sql %}
+CREATE TABLE person (name STRING, age INT);
+INSERT INTO person VALUES ('Zen Hui', 25),
+ ('Anil B', 18),
+ ('Shone S', 16),
+ ('Mike A', 25),
+ ('John A', 18),
+ ('Jack N', 16);
+
+-- Select the first two rows.
+SELECT name, age FROM person ORDER BY name LIMIT 2;
+
+ +------+---+
+ |name |age|
+ +------+---+
+ |Anil B|18 |
+ |Jack N|16 |
+ +------+---+
+
+-- Specifying ALL option on LIMIT returns all the rows.
+SELECT name, age FROM person ORDER BY name LIMIT ALL;
+
+ +-------+---+
+ |name |age|
+ +-------+---+
+ |Anil B |18 |
+ |Jack N |16 |
+ |John A |18 |
+ |Mike A |25 |
+ |Shone S|16 |
+ |Zen Hui|25 |
+ +-------+---+
+
+-- A function expression as a input to limit.
Review comment:
```a input``` -> ```an input```?
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