[SPARK-20476][SQL] Block users to create a table that use commas in the column names

### What changes were proposed in this pull request?
```SQL
hive> create table t1(`a,` string);
OK
Time taken: 1.399 seconds

hive> create table t2(`a,` string, b string);
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. java.lang.RuntimeException: MetaException(message:org.apache.hadoop.hive.serde2.SerDeException org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe: columns has 3 elements while columns.types has 2 elements!)

hive> create table t2(`a,` string, b string) stored as parquet;
FAILED: Execution Error, return code 1 from org.apache.hadoop.hive.ql.exec.DDLTask. java.lang.IllegalArgumentException: ParquetHiveSerde initialization failed. Number of column name and column type differs. columnNames = [a, , b], columnTypes = [string, string]
```
It has a bug in Hive metastore.

When users do not provide alias name in the SELECT query, we call `toPrettySQL` to generate the alias name. For example, the string `get_json_object(jstring, '$.f1')` will be the alias name for the function call in the statement
```SQL
SELECT key, get_json_object(jstring, '$.f1') FROM tempView
```
Above is not an issue for the SELECT query statements. However, for CTAS, we hit the issue due to a bug in Hive metastore. Hive metastore does not like the column names containing commas and returned a confusing error message, like:
```
17/04/26 23:12:56 ERROR [hive.log(397) -- main]: error in initSerDe: org.apache.hadoop.hive.serde2.SerDeException org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe: columns has 2 elements while columns.types has 1 elements!
org.apache.hadoop.hive.serde2.SerDeException: org.apache.hadoop.hive.serde2.lazy.LazySimpleSerDe: columns has 2 elements while columns.types has 1 elements!
```

Thus, this PR is to block users to create a table in Hive metastore when the table table has a column containing commas in the name.

### How was this patch tested?
Added a test case

Author: Xiao Li <gatorsmile@gmail.com>

Closes #17781 from gatorsmile/blockIllegalColumnNames.

Author: gatorsmile

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveExternalCatalog.scala

@@ -137,6 +137,22 @@ private[spark] class HiveExternalCatalog(conf: SparkConf, hadoopConf: Configurat
     }
   }
 
+  /**
+   * Checks the validity of column names. Hive metastore disallows the table to use comma in
+   * data column names. Partition columns do not have such a restriction. Views do not have such
+   * a restriction.
+   */
+  private def verifyColumnNames(table: CatalogTable): Unit = {
+    if (table.tableType != VIEW) {
+      table.dataSchema.map(_.name).foreach { colName =>
+        if (colName.contains(",")) {
+          throw new AnalysisException("Cannot create a table having a column whose name contains " +
+            s"commas in Hive metastore. Table: ${table.identifier}; Column: $colName")
+        }
+      }
+    }
+  }
+
   // --------------------------------------------------------------------------
   // Databases
   // --------------------------------------------------------------------------
@@ -202,6 +218,7 @@ private[spark] class HiveExternalCatalog(conf: SparkConf, hadoopConf: Configurat
     val table = tableDefinition.identifier.table
     requireDbExists(db)
     verifyTableProperties(tableDefinition)
+    verifyColumnNames(tableDefinition)
 
     if (tableExists(db, table) && !ignoreIfExists) {
       throw new TableAlreadyExistsException(db = db, table = table)
@@ -614,6 +631,7 @@ private[spark] class HiveExternalCatalog(conf: SparkConf, hadoopConf: Configurat
     requireTableExists(db, table)
     val rawTable = getRawTable(db, table)
     val withNewSchema = rawTable.copy(schema = schema)
+    verifyColumnNames(withNewSchema)
     // Add table metadata such as table schema, partition columns, etc. to table properties.
     val updatedTable = withNewSchema.copy(
       properties = withNewSchema.properties ++ tableMetaToTableProps(withNewSchema))

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala

@@ -1976,6 +1976,30 @@ class SQLQuerySuite extends QueryTest with SQLTestUtils with TestHiveSingleton {
     }
   }
 
+  test("Auto alias construction of get_json_object") {
+    val df = Seq(("1", """{"f1": "value1", "f5": 5.23}""")).toDF("key", "jstring")
+    val expectedMsg = "Cannot create a table having a column whose name contains commas " +
+      "in Hive metastore. Table: `default`.`t`; Column: get_json_object(jstring, $.f1)"
+
+    withTable("t") {
+      val e = intercept[AnalysisException] {
+        df.select($"key", functions.get_json_object($"jstring", "$.f1"))
+          .write.format("hive").saveAsTable("t")
+      }.getMessage
+      assert(e.contains(expectedMsg))
+    }
+
+    withTempView("tempView") {
+      withTable("t") {
+        df.createTempView("tempView")
+        val e = intercept[AnalysisException] {
+          sql("CREATE TABLE t AS SELECT key, get_json_object(jstring, '$.f1') FROM tempView")
+        }.getMessage
+        assert(e.contains(expectedMsg))
+      }
+    }
+  }
+
   test("SPARK-19912 String literals should be escaped for Hive metastore partition pruning") {
     withTable("spark_19912") {
       Seq(