@@ -423,11 +423,47 @@ Table result = in.groupBy("a").select("a, b.sum as d");
...
@@ -423,11 +423,47 @@ Table result = in.groupBy("a").select("a, b.sum as d");
<tr>
<tr>
<td><strong>Join</strong></td>
<td><strong>Join</strong></td>
<td>
<td>
<p>Similar to a SQL JOIN clause. Joins two tables. Both tables must have distinct field names and an equality join predicate must be defined using a where or filter operator.</p>
<p>Similar to a SQL JOIN clause. Joins two tables. Both tables must have distinct field names and at least one equality join predicate must be defined through join operator or using a where or filter operator.</p>
{% highlight java %}
{% highlight java %}
Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "d, e, f");
Table right = tableEnv.fromDataSet(ds2, "d, e, f");
Table result = left.join(right).where("a = d").select("a, b, e");
Table result = left.join(right).where("a = d").select("a, b, e");
{% endhighlight %}
</td>
</tr>
<tr>
<td><strong>LeftOuterJoin</strong></td>
<td>
<p>Similar to a SQL LEFT OUTER JOIN clause. Joins two tables. Both tables must have distinct field names and at least one equality join predicate must be defined.</p>
{% highlight java %}
Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "d, e, f");
Table result = left.leftOuterJoin(right, "a = d").select("a, b, e");
{% endhighlight %}
</td>
</tr>
<tr>
<td><strong>RightOuterJoin</strong></td>
<td>
<p>Similar to a SQL RIGHT OUTER JOIN clause. Joins two tables. Both tables must have distinct field names and at least one equality join predicate must be defined.</p>
{% highlight java %}
Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "d, e, f");
Table result = left.rightOuterJoin(right, "a = d").select("a, b, e");
{% endhighlight %}
</td>
</tr>
<tr>
<td><strong>FullOuterJoin</strong></td>
<td>
<p>Similar to a SQL FULL OUTER JOIN clause. Joins two tables. Both tables must have distinct field names and at least one equality join predicate must be defined.</p>
{% highlight java %}
Table left = tableEnv.fromDataSet(ds1, "a, b, c");
Table right = tableEnv.fromDataSet(ds2, "d, e, f");
Table result = left.fullOuterJoin(right, "a = d").select("a, b, e");
{% endhighlight %}
{% endhighlight %}
</td>
</td>
</tr>
</tr>
...
@@ -551,6 +587,42 @@ val result = in.groupBy('a).select('a, 'b.sum as 'd);
...
@@ -551,6 +587,42 @@ val result = in.groupBy('a).select('a, 'b.sum as 'd);
val left = ds1.toTable(tableEnv, 'a, 'b, 'c);
val left = ds1.toTable(tableEnv, 'a, 'b, 'c);
val right = ds2.toTable(tableEnv, 'd, 'e, 'f);
val right = ds2.toTable(tableEnv, 'd, 'e, 'f);
val result = left.join(right).where('a === 'd).select('a, 'b, 'e);
val result = left.join(right).where('a === 'd).select('a, 'b, 'e);
{% endhighlight %}
</td>
</tr>
<tr>
<td><strong>LeftOuterJoin</strong></td>
<td>
<p>Similar to a SQL LEFT OUTER JOIN clause. Joins two tables. Both tables must have distinct field names and at least one equality join predicate must be defined.</p>
{% highlight scala %}
val left = tableEnv.fromDataSet(ds1, 'a, 'b, 'c)
val right = tableEnv.fromDataSet(ds2, 'd, 'e, 'f)
val result = left.leftOuterJoin(right, 'a === 'd).select('a, 'b, 'e)
{% endhighlight %}
</td>
</tr>
<tr>
<td><strong>RightOuterJoin</strong></td>
<td>
<p>Similar to a SQL RIGHT OUTER JOIN clause. Joins two tables. Both tables must have distinct field names and at least one equality join predicate must be defined.</p>
{% highlight scala %}
val left = tableEnv.fromDataSet(ds1, 'a, 'b, 'c)
val right = tableEnv.fromDataSet(ds2, 'd, 'e, 'f)
val result = left.rightOuterJoin(right, 'a === 'd).select('a, 'b, 'e)
{% endhighlight %}
</td>
</tr>
<tr>
<td><strong>FullOuterJoin</strong></td>
<td>
<p>Similar to a SQL FULL OUTER JOIN clause. Joins two tables. Both tables must have distinct field names and at least one equality join predicate must be defined.</p>
{% highlight scala %}
val left = tableEnv.fromDataSet(ds1, 'a, 'b, 'c)
val right = tableEnv.fromDataSet(ds2, 'd, 'e, 'f)
val result = left.fullOuterJoin(right, 'a === 'd).select('a, 'b, 'e)
{% endhighlight %}
{% endhighlight %}
</td>
</td>
</tr>
</tr>
...
@@ -711,13 +783,12 @@ Among others, the following SQL features are not supported, yet:
...
@@ -711,13 +783,12 @@ Among others, the following SQL features are not supported, yet:
- Time data types (`DATE`, `TIME`, `TIMESTAMP`, `INTERVAL`) and `DECIMAL` types
- Time data types (`DATE`, `TIME`, `TIMESTAMP`, `INTERVAL`) and `DECIMAL` types
*Note: Tables are joined in the order in which they are specified in the `FROM` clause. In some cases the table order must be manually tweaked to resolve Cartesian products. Certain rewrites during optimization (e.g., subquery decorrelation) can result in unsupported operations such as outer joins.*
*Note: Tables are joined in the order in which they are specified in the `FROM` clause. In some cases the table order must be manually tweaked to resolve Cartesian products.*
