### What changes were proposed in this pull request?
The documentation of the Spark SQL null semantics states that "NULL AND False" yields NULL. This is incorrect. "NULL AND False" yields False.
```
Seq[(java.lang.Boolean, java.lang.Boolean)](
(null, false)
)
.toDF("left_operand", "right_operand")
.withColumn("AND", 'left_operand && 'right_operand)
.show(truncate = false)
+------------+-------------+-----+
|left_operand|right_operand|AND |
+------------+-------------+-----+
|null |false |false|
+------------+-------------+-----+
```
I propose the documentation be updated to reflect that "NULL AND False" yields False.
This contribution is my original work and I license it to the project under the project’s open source license.
### Why are the changes needed?
This change improves the accuracy of the documentation.
### Does this PR introduce _any_ user-facing change?
Yes. This PR introduces a fix to the documentation.
### How was this patch tested?
Since this is only a documentation change, no tests were added.
Closes#30161 from stwhit/SPARK-33246.
Authored-by: Stuart White <stuart@spotright.com>
Signed-off-by: Takeshi Yamamuro <yamamuro@apache.org>
### What changes were proposed in this pull request?
Remove the unneeded embedded inline HTML markup by using the basic markdown syntax.
Please see #28414
### Why are the changes needed?
Make the doc cleaner and easily editable by MD editors.
### Does this PR introduce _any_ user-facing change?
No
### How was this patch tested?
Manually build and check
Closes#28451 from huaxingao/html_cleanup.
Authored-by: Huaxin Gao <huaxing@us.ibm.com>
Signed-off-by: Sean Owen <srowen@gmail.com>
### What changes were proposed in this pull request?
This PR intends to clean up the SQL documents in `doc/sql-ref*`.
Main changes are as follows;
- Fixes wrong syntaxes and capitalize sub-titles
- Adds some DDL queries in `Examples` so that users can run examples there
- Makes query output in `Examples` follows the `Dataset.showString` (right-aligned) format
- Adds/Removes spaces, Indents, or blank lines to follow the format below;
```
---
license...
---
### Description
Writes what's the syntax is.
### Syntax
{% highlight sql %}
SELECT...
WHERE... // 4 indents after the second line
...
{% endhighlight %}
### Parameters
<dl>
<dt><code><em>Param Name</em></code></dt>
<dd>
Param Description
</dd>
...
</dl>
### Examples
{% highlight sql %}
-- It is better that users are able to execute example queries here.
-- So, we prepare test data in the first section if possible.
CREATE TABLE t (key STRING, value DOUBLE);
INSERT INTO t VALUES
('a', 1.0), ('a', 2.0), ('b', 3.0), ('c', 4.0);
-- query output has 2 indents and it follows the `Dataset.showString`
-- format (right-aligned).
SELECT * FROM t;
+---+-----+
|key|value|
+---+-----+
| a| 1.0|
| a| 2.0|
| b| 3.0|
| c| 4.0|
+---+-----+
-- Query statements after the second line have 4 indents.
SELECT key, SUM(value)
FROM t
GROUP BY key;
+---+----------+
|key|sum(value)|
+---+----------+
| c| 4.0|
| b| 3.0|
| a| 3.0|
+---+----------+
...
{% endhighlight %}
### Related Statements
* [XXX](xxx.html)
* ...
```
### Why are the changes needed?
The most changes of this PR are pretty minor, but I think the consistent formats/rules to write documents are important for long-term maintenance in our community
### Does this PR introduce any user-facing change?
Yes.
### How was this patch tested?
Manually checked.
Closes#28151 from maropu/MakeRightAligned.
Authored-by: Takeshi Yamamuro <yamamuro@apache.org>
Signed-off-by: Sean Owen <srowen@gmail.com>
### What changes were proposed in this pull request?
This PR intends to fix typos and phrases in the `/docs` directory. To find them, I run the Intellij typo checker.
### Why are the changes needed?
For better documents.
### Does this PR introduce any user-facing change?
No.
### How was this patch tested?
N/A
Closes#27819 from maropu/TypoFix-20200306.
Authored-by: Takeshi Yamamuro <yamamuro@apache.org>
Signed-off-by: Gengliang Wang <gengliang.wang@databricks.com>
### What changes were proposed in this pull request?
Fixed typo in `docs` directory and in other directories
1. Find typo in `docs` and apply fixes to files in all directories
2. Fix `the the` -> `the`
### Why are the changes needed?
Better readability of documents
### Does this PR introduce any user-facing change?
No
### How was this patch tested?
No test needed
Closes#26976 from kiszk/typo_20191221.
Authored-by: Kazuaki Ishizaki <ishizaki@jp.ibm.com>
Signed-off-by: Dongjoon Hyun <dhyun@apple.com>
### What changes were proposed in this pull request?
Enhancement of the SQL NULL Semantics document: sql-ref-null-semantics.html.
### Why are the changes needed?
Clarify the behavior of `UNKNOWN` for both `EXIST` and `IN` operation.
### Does this PR introduce any user-facing change?
No.
### How was this patch tested?
Doc changes only.
Closes#26837 from xuanyuanking/SPARK-30207.
Authored-by: Yuanjian Li <xyliyuanjian@gmail.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>