d0272b4365
## What changes were proposed in this pull request?
Aggregation Without Window/GroupBy expressions will fail in `checkAnalysis`, the error message is a bit misleading, we should generate a more specific error message for this case.
For example,
```
spark.read.load("/some-data")
.withColumn("date_dt", to_date($"date"))
.withColumn("year", year($"date_dt"))
.withColumn("week", weekofyear($"date_dt"))
.withColumn("user_count", count($"userId"))
.withColumn("daily_max_in_week", max($"user_count").over(weeklyWindow))
)
```
creates the following output:
```
org.apache.spark.sql.AnalysisException: expression '`randomColumn`' is neither present in the group by, nor is it an aggregate function. Add to group by or wrap in first() (or first_value) if you don't care which value you get.;
```
In the error message above, `randomColumn` doesn't appear in the query(acturally it's added by function `withColumn`), so the message is not enough for the user to address the problem.
## How was this patch tested?
Manually test
Before:
```
scala> spark.sql("select col, count(col) from tbl")
org.apache.spark.sql.AnalysisException: expression 'tbl.`col`' is neither present in the group by, nor is it an aggregate function. Add to group by or wrap in first() (or first_value) if you don't care which value you get.;;
```
After:
```
scala> spark.sql("select col, count(col) from tbl")
org.apache.spark.sql.AnalysisException: grouping expressions sequence is empty, and 'tbl.`col`' is not an aggregate function. Wrap '(count(col#231L) AS count(col)#239L)' in windowing function(s) or wrap 'tbl.`col`' in first() (or first_value) if you don't care which value you get.;;
```
Also add new test sqls in `group-by.sql`.
Author: jiangxingbo <jiangxb1987@gmail.com>
Closes #15672 from jiangxb1987/groupBy-empty.
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| hive | ||
| hive-thriftserver | ||
| 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.