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Posted to issues@flink.apache.org by GitBox <gi...@apache.org> on 2018/10/10 11:11:11 UTC
[GitHub] asfgit closed pull request #6744: [FLINK-10379][docs,
table] Fix Table Function docs
asfgit closed pull request #6744: [FLINK-10379][docs,table] Fix Table Function docs
URL: https://github.com/apache/flink/pull/6744
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diff --git a/docs/dev/table/sql.md b/docs/dev/table/sql.md
index a9fd94f10d5..fb23511d78e 100644
--- a/docs/dev/table/sql.md
+++ b/docs/dev/table/sql.md
@@ -483,11 +483,11 @@ FROM Orders CROSS JOIN UNNEST(tags) AS t (tag)
</tr>
<tr>
<td>
- <strong>Join with User Defined Table Functions (UDTF)</strong><br>
+ <strong>Join with Table Function</strong><br>
<span class="label label-primary">Batch</span> <span class="label label-primary">Streaming</span>
</td>
<td>
- <p>UDTFs must be registered in the TableEnvironment. See the <a href="udfs.html">UDF documentation</a> for details on how to specify and register UDTFs. </p>
+ <p>To use User-Defined Table Function in SQL it must be registered in the TableEnvironment. See the <a href="udfs.html">UDF documentation</a> for details on how to specify and register UDTFs. </p>
<p>Inner Join</p>
{% highlight sql %}
SELECT users, tag
diff --git a/docs/dev/table/tableApi.md b/docs/dev/table/tableApi.md
index f50b0f54554..c5aa160cf1f 100644
--- a/docs/dev/table/tableApi.md
+++ b/docs/dev/table/tableApi.md
@@ -627,29 +627,29 @@ Table result = left.join(right)
</td>
</tr>
<tr>
- <td>
- <strong>TableFunction Inner Join</strong><br>
+ <td>
+ <strong>Inner Join with Table Function</strong><br>
<span class="label label-primary">Batch</span> <span class="label label-primary">Streaming</span>
</td>
<td>
<p>Joins a table with a the results of a table function. Each row of the left (outer) table is joined with all rows produced by the corresponding call of the table function. A row of the left (outer) table is dropped, if its table function call returns an empty result.
</p>
{% highlight java %}
-// register function
+// register User-Defined Table Function
TableFunction<String> split = new MySplitUDTF();
-tEnv.registerFunction("split", split);
+tableEnv.registerFunction("split", split);
// join
Table orders = tableEnv.scan("Orders");
Table result = orders
- .join(new Table(tEnv, "split(c)").as("s", "t", "v"))
+ .join(new Table(tableEnv, "split(c)").as("s", "t", "v"))
.select("a, b, s, t, v");
{% endhighlight %}
</td>
</tr>
<tr>
- <td>
- <strong>TableFunction Left Outer Join</strong><br>
+ <td>
+ <strong>Left Outer Join with Table Function</strong><br>
<span class="label label-primary">Batch</span> <span class="label label-primary">Streaming</span>
</td>
<td>
@@ -657,14 +657,14 @@ Table result = orders
<p><b>Note:</b> Currently, the predicate of a table function left outer join can only be empty or literal <code>true</code>.</p>
</p>
{% highlight java %}
-// register function
+// register User-Defined Table Function
TableFunction<String> split = new MySplitUDTF();
-tEnv.registerFunction("split", split);
+tableEnv.registerFunction("split", split);
// join
Table orders = tableEnv.scan("Orders");
Table result = orders
- .leftOuterJoin(new Table(tEnv, "split(c)").as("s", "t", "v"))
+ .leftOuterJoin(new Table(tableEnv, "split(c)").as("s", "t", "v"))
.select("a, b, s, t, v");
{% endhighlight %}
</td>
@@ -729,7 +729,7 @@ val fullOuterResult = left.fullOuterJoin(right, 'a === 'd).select('a, 'b, 'e)
<td>
<p><b>Note:</b> Time-windowed joins are a subset of regular joins that can be processed in a streaming fashion.</p>
- <p>A time-windowed join requires at least one equi-join predicate and a join condition that bounds the time on both sides. Such a condition can be defined by two appropriate range predicates (<code><, <=, >=, ></code>) or a single equality predicate that compares <a href="streaming.html#time-attributes">time attributes</a> of the same type (i.e., processing time or event time) of both input tables.</p>
+ <p>A time-windowed join requires at least one equi-join predicate and a join condition that bounds the time on both sides. Such a condition can be defined by two appropriate range predicates (<code><, <=, >=, ></code>) or a single equality predicate that compares <a href="streaming.html#time-attributes">time attributes</a> of the same type (i.e., processing time or event time) of both input tables.</p>
<p>For example, the following predicates are valid window join conditions:</p>
<ul>
@@ -748,15 +748,15 @@ val result = left.join(right)
</td>
</tr>
<tr>
- <td>
- <strong>TableFunction Inner Join</strong><br>
+ <td>
+ <strong>Inner Join with Table Function</strong><br>
<span class="label label-primary">Batch</span> <span class="label label-primary">Streaming</span>
</td>
<td>
<p>Joins a table with a the results of a table function. Each row of the left (outer) table is joined with all rows produced by the corresponding call of the table function. A row of the left (outer) table is dropped, if its table function call returns an empty result.
</p>
{% highlight scala %}
-// instantiate function
+// instantiate User-Defined Table Function
val split: TableFunction[_] = new MySplitUDTF()
// join
@@ -767,15 +767,15 @@ val result: Table = table
</td>
</tr>
<tr>
- <td>
- <strong>TableFunction Left Outer Join</strong><br>
+ <td>
+ <strong>Left Outer Join with Table Function</strong><br>
<span class="label label-primary">Batch</span> <span class="label label-primary">Streaming</span></td>
<td>
<p>Joins a table with a the results of a table function. Each row of the left (outer) table is joined with all rows produced by the corresponding call of the table function. If a table function call returns an empty result, the corresponding outer row is preserved and the result padded with null values.
<p><b>Note:</b> Currently, the predicate of a table function left outer join can only be empty or literal <code>true</code>.</p>
</p>
{% highlight scala %}
-// instantiate function
+// instantiate User-Defined Table Function
val split: TableFunction[_] = new MySplitUDTF()
// join
diff --git a/docs/dev/table/udfs.md b/docs/dev/table/udfs.md
index 7dce8009777..20bf49d5999 100644
--- a/docs/dev/table/udfs.md
+++ b/docs/dev/table/udfs.md
@@ -141,7 +141,7 @@ Similar to a user-defined scalar function, a user-defined table function takes z
In order to define a table function one has to extend the base class `TableFunction` in `org.apache.flink.table.functions` and implement (one or more) evaluation methods. The behavior of a table function is determined by its evaluation methods. An evaluation method must be declared `public` and named `eval`. The `TableFunction` can be overloaded by implementing multiple methods named `eval`. The parameter types of the evaluation methods determine all valid parameters of the table function. Evaluation methods can also support variable arguments, such as `eval(String... strs)`. The type of the returned table is determined by the generic type of `TableFunction`. Evaluation methods emit output rows using the protected `collect(T)` method.
-In the Table API, a table function is used with `.join(Expression)` or `.leftOuterJoin(Expression)` for Scala users and `.join(String)` or `.leftOuterJoin(String)` for Java users. The `join` operator (cross) joins each row from the outer table (table on the left of the operator) with all rows produced by the table-valued function (which is on the right side of the operator). The `leftOuterJoin` operator joins each row from the outer table (table on the left of the operator) with all rows produced by the table-valued function (which is on the right side of the operator) and preserves outer rows for which the table function returns an empty table. In SQL use `LATERAL TABLE(<TableFunction>)` with CROSS JOIN and LEFT JOIN with an ON TRUE join condition (see examples below).
+In the Table API, a table function is used with `.join(Table)` or `.leftOuterJoin(Table)`. The `join` operator (cross) joins each row from the outer table (table on the left of the operator) with all rows produced by the table-valued function (which is on the right side of the operator). The `leftOuterJoin` operator joins each row from the outer table (table on the left of the operator) with all rows produced by the table-valued function (which is on the right side of the operator) and preserves outer rows for which the table function returns an empty table. In SQL use `LATERAL TABLE(<TableFunction>)` with CROSS JOIN and LEFT JOIN with an ON TRUE join condition (see examples below).
The following example shows how to define table-valued function, register it in the TableEnvironment, and call it in a query. Note that you can configure your table function via a constructor before it is registered:
@@ -171,8 +171,10 @@ Table myTable = ... // table schema: [a: String]
tableEnv.registerFunction("split", new Split("#"));
// Use the table function in the Java Table API. "as" specifies the field names of the table.
-myTable.join("split(a) as (word, length)").select("a, word, length");
-myTable.leftOuterJoin("split(a) as (word, length)").select("a, word, length");
+myTable.join(new Table(tableEnv, "split(a) as (word, length)"))
+ .select("a, word, length");
+myTable.leftOuterJoin(new Table(tableEnv, "split(a) as (word, length)"))
+ .select("a, word, length");
// Use the table function in SQL with LATERAL and TABLE keywords.
// CROSS JOIN a table function (equivalent to "join" in Table API).
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/TableFunction.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/TableFunction.scala
index d80ec4710d2..489b0e66a18 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/TableFunction.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/TableFunction.scala
@@ -69,7 +69,7 @@ import org.apache.flink.util.Collector
*
* // for Java users
* tEnv.registerFunction("split", new Split()) // register table function first
- * table.join("split(a) as (s)").select("a, s")
+ * table.join(new Table(tEnv, "split(a) as (s)")).select("a, s")
*
* // for SQL users
* tEnv.registerFunction("split", new Split()) // register table function first
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