You are viewing a plain text version of this content. The canonical link for it is here.
Posted to commits@beam.apache.org by me...@apache.org on 2017/08/26 04:38:04 UTC
[beam-site] branch asf-site updated (dbb8f55 -> 6386ac2)
This is an automated email from the ASF dual-hosted git repository.
mergebot-role pushed a change to branch asf-site
in repository https://gitbox.apache.org/repos/asf/beam-site.git.
from dbb8f55 Prepare repository for deployment.
add c51fa52 add SQL grammar in BNF
add 3e8980e correct the syntax of ORDER_BY LIMIT
add ec83da1 This closes #300
new 6386ac2 Prepare repository for deployment.
The 1 revisions listed above as "new" are entirely new to this
repository and will be described in separate emails. The revisions
listed as "add" were already present in the repository and have only
been added to this reference.
Summary of changes:
content/documentation/dsls/sql/index.html | 73 +++++++++++++++++++++++++------
src/documentation/dsls/sql.md | 73 +++++++++++++++++++++++++------
2 files changed, 118 insertions(+), 28 deletions(-)
--
To stop receiving notification emails like this one, please contact
['"commits@beam.apache.org" <co...@beam.apache.org>'].
[beam-site] 01/01: Prepare repository for deployment.
Posted by me...@apache.org.
This is an automated email from the ASF dual-hosted git repository.
mergebot-role pushed a commit to branch asf-site
in repository https://gitbox.apache.org/repos/asf/beam-site.git
commit 6386ac2149c4320f0891c33b545bbf5b0bc8287a
Author: Mergebot <me...@apache.org>
AuthorDate: Sat Aug 26 04:38:02 2017 +0000
Prepare repository for deployment.
---
content/documentation/dsls/sql/index.html | 73 +++++++++++++++++++++++++------
1 file changed, 59 insertions(+), 14 deletions(-)
diff --git a/content/documentation/dsls/sql/index.html b/content/documentation/dsls/sql/index.html
index af40420..dc501b5 100644
--- a/content/documentation/dsls/sql/index.html
+++ b/content/documentation/dsls/sql/index.html
@@ -266,18 +266,65 @@ PCollection<BeamRecord> output = namesAndFoods.apply(
<p><a href="https://github.com/apache/beam/blob/DSL_SQL/sdks/java/extensions/sql/src/main/java/org/apache/beam/sdk/extensions/sql/example/BeamSqlExample.java">BeamSqlExample</a> in the code repository shows basic usage of both APIs.</p>
<h1 id="a-namefunctionalitya3-functionality-in-beam-sql"><a name="functionality"></a>3. Functionality in Beam SQL</h1>
-<p>Just as the unified model for both bounded and unbounded data in Beam, SQL DSL provides the same functionalities for bounded and unbounded <code class="highlighter-rouge">PCollection</code> as well.</p>
+<p>Just as the unified model for both bounded and unbounded data in Beam, SQL DSL provides the same functionalities for bounded and unbounded <code class="highlighter-rouge">PCollection</code> as well. Here’s the supported SQL grammar supported in <a href="http://en.wikipedia.org/wiki/Backus%E2%80%93Naur_Form">BNF</a>-like form. An <code class="highlighter-rouge">UnsupportedOperationException</code> is thrown for unsupported features.</p>
+
+<div class="highlighter-rouge"><pre class="highlight"><code>query:
+ {
+ select
+ | query UNION [ ALL ] query
+ | query MINUS [ ALL ] query
+ | query INTERSECT [ ALL ] query
+ }
+ [ ORDER BY orderItem [, orderItem ]* LIMIT count [OFFSET offset] ]
+
+orderItem:
+ expression [ ASC | DESC ]
+
+select:
+ SELECT
+ { * | projectItem [, projectItem ]* }
+ FROM tableExpression
+ [ WHERE booleanExpression ]
+ [ GROUP BY { groupItem [, groupItem ]* } ]
+ [ HAVING booleanExpression ]
+
+projectItem:
+ expression [ [ AS ] columnAlias ]
+ | tableAlias . *
+
+tableExpression:
+ tableReference [, tableReference ]*
+ | tableExpression [ ( LEFT | RIGHT ) [ OUTER ] ] JOIN tableExpression [ joinCondition ]
+
+booleanExpression:
+ expression [ IS NULL | IS NOT NULL ]
+ | expression [ > | >= | = | < | <= | <> ] expression
+ | booleanExpression [ AND | OR ] booleanExpression
+ | NOT booleanExpression
+ | '(' booleanExpression ')'
+
+joinCondition:
+ ON booleanExpression
+
+tableReference:
+ tableName [ [ AS ] alias ]
+
+values:
+ VALUES expression [, expression ]*
+
+groupItem:
+ expression
+ | '(' expression [, expression ]* ')'
+ | HOP '(' expression [, expression ]* ')'
+ | TUMBLE '(' expression [, expression ]* ')'
+ | SESSION '(' expression [, expression ]* ')'
-<p>Note that, SQL support is not fully completed. Queries that include unsupported features would cause an <code class="highlighter-rouge">UnsupportedOperationException</code>.</p>
+</code></pre>
+</div>
<h2 id="a-namefeaturesa31-supported-features"><a name="features"></a>3.1. Supported Features</h2>
-<p>The following features are supported in current repository:</p>
-
-<p><strong>1. filter clauses;</strong></p>
-<p><strong>2. data field projections;</strong></p>
-
-<p><strong>3. aggregations;</strong></p>
+<p><strong>1. aggregations;</strong></p>
<p>Beam SQL supports aggregation functions with group_by in global_window, fixed_window, sliding_window and session_window. A field with type <code class="highlighter-rouge">TIMESTAMP</code> is required to specify fixed_window/sliding_window/session_window. The field is used as event timestamp for rows. See below for several examples:</p>
@@ -305,7 +352,7 @@ SELECT f_int, COUNT(*) AS `size` FROM PCOLLECTION GROUP BY f_int, SESSION(f_time
</code></pre>
</div>
-<p><strong>4. Join (inner, left_outer, right_outer);</strong></p>
+<p><strong>2. Join (inner, left_outer, right_outer);</strong></p>
<p>The scenarios of join can be categorized into 3 cases:</p>
@@ -324,9 +371,7 @@ SELECT f_int, COUNT(*) AS `size` FROM PCOLLECTION GROUP BY f_int, SESSION(f_time
<li>window/trigger is inherented from upstreams, which should be consistent;</li>
</ul>
-<p><strong>5. built-in SQL functions</strong></p>
-
-<p><strong>6. User Defined Function (UDF) and User Defined Aggregate Function (UDAF);</strong></p>
+<p><strong>3. User Defined Function (UDF) and User Defined Aggregate Function (UDAF);</strong></p>
<p>If the required function is not available, developers can register their own UDF(for scalar function) and UDAF(for aggregation function).</p>
@@ -405,7 +450,7 @@ PCollection<BeamSqlRow> result =
</code></pre>
</div>
-<h2 id="a-namedata-typea33-data-types"><a name="data-type"></a>3.3. Data Types</h2>
+<h2 id="a-namedata-typea32-data-types"><a name="data-type"></a>3.2. Data Types</h2>
<p>Each type in Beam SQL maps to a Java class to holds the value in <code class="highlighter-rouge">BeamRecord</code>. The following table lists the relation between SQL types and Java classes, which are supported in current repository:</p>
<table class="table">
@@ -455,7 +500,7 @@ PCollection<BeamSqlRow> result =
</tbody>
</table>
-<h2 id="a-namebuilt-in-functionsa34-built-in-sql-functions"><a name="built-in-functions"></a>3.4. built-in SQL functions</h2>
+<h2 id="a-namebuilt-in-functionsa33-built-in-sql-functions"><a name="built-in-functions"></a>3.3. built-in SQL functions</h2>
<p>Beam SQL has implemented lots of build-in functions defined in <a href="http://calcite.apache.org">Apache Calcite</a>. The available functions are listed as below:</p>
--
To stop receiving notification emails like this one, please contact
"commits@beam.apache.org" <co...@beam.apache.org>.