2250cb75b9
## What changes were proposed in this pull request?
This pr fixed the issue when casting structs into strings;
```
scala> val df = Seq(((1, "a"), 0), ((2, "b"), 0)).toDF("a", "b")
scala> df.write.saveAsTable("t")
scala> sql("SELECT CAST(a AS STRING) FROM t").show
+-------------------+
| a|
+-------------------+
|[0,1,1800000001,61]|
|[0,2,1800000001,62]|
+-------------------+
```
This pr modified the result into;
```
+------+
| a|
+------+
|[1, a]|
|[2, b]|
+------+
```
## How was this patch tested?
Added tests in `CastSuite`.
Author: Takeshi Yamamuro <yamamuro@apache.org>
Closes #20176 from maropu/SPARK-22981.
|
||
|---|---|---|
| .. | ||
| catalyst | ||
| core | ||
| hive | ||
| hive-thriftserver | ||
| create-docs.sh | ||
| gen-sql-markdown.py | ||
| mkdocs.yml | ||
| README.md | ||
Spark SQL
This module provides support for executing relational queries expressed in either SQL or the DataFrame/Dataset API.
Spark SQL is broken up into four subprojects:
- Catalyst (sql/catalyst) - An implementation-agnostic framework for manipulating trees of relational operators and expressions.
- Execution (sql/core) - A query planner / execution engine for translating Catalyst's logical query plans into Spark RDDs. This component also includes a new public interface, SQLContext, that allows users to execute SQL or LINQ statements against existing RDDs and Parquet files.
- Hive Support (sql/hive) - Includes an extension of SQLContext called HiveContext that allows users to write queries using a subset of HiveQL and access data from a Hive Metastore using Hive SerDes. There are also wrappers that allows users to run queries that include Hive UDFs, UDAFs, and UDTFs.
- HiveServer and CLI support (sql/hive-thriftserver) - Includes support for the SQL CLI (bin/spark-sql) and a HiveServer2 (for JDBC/ODBC) compatible server.
Running sql/create-docs.sh generates SQL documentation for built-in functions under sql/site.