[SPARK-14842][SQL] Implement view creation in sql/core

## What changes were proposed in this pull request?
This patch re-implements view creation command in sql/core, based on the pre-existing view creation command in the Hive module. This consolidates the view creation logical command and physical command into a single one, called CreateViewCommand.

## How was this patch tested?
All the code should've been tested by existing tests.

Author: Reynold Xin <rxin@databricks.com>

Closes #12615 from rxin/SPARK-14842-2.

2 files changed, 5 insertions, 0 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/types/DataType.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/types/DataType.scala
index 3d4a02b0ff..4fc65cbce1 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/types/DataType.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/types/DataType.scala
@@ -62,6 +62,9 @@ abstract class DataType extends AbstractDataType {
   /** Readable string representation for the type. */
   def simpleString: String = typeName
 
+  /** String representation for the type saved in external catalogs. */
+  def catalogString: String = simpleString
+
   /** Readable string representation for the type with truncation */
   private[sql] def simpleString(maxNumberFields: Int): String = simpleString
 
diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/types/UserDefinedType.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/types/UserDefinedType.scala
index 71a9b9f808..aa36121bde 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/types/UserDefinedType.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/types/UserDefinedType.scala
@@ -91,6 +91,8 @@ abstract class UserDefinedType[UserType >: Null] extends DataType with Serializa
     case that: UserDefinedType[_] => this.acceptsType(that)
     case _ => false
   }
+
+  override def catalogString: String = sqlType.simpleString
 }
 
 /**