code refactor.

Author: jiangxb1987

sql/core/src/main/scala/org/apache/spark/sql/execution/command/views.scala

@@ -165,7 +165,7 @@ case class CreateViewCommand(
         throw new AnalysisException(s"$name is not a view")
       } else if (replace) {
         // Handles `CREATE OR REPLACE VIEW v0 AS SELECT ...`
-        catalog.alterTable(prepareTable(sparkSession, aliasedPlan))
+        catalog.alterTable(prepareTable(sparkSession, aliasedPlan, analyzedPlan))
       } else {
         // Handles `CREATE VIEW v0 AS SELECT ...`. Throws exception when the target view already
         // exists.
@@ -175,7 +175,8 @@ case class CreateViewCommand(
       }
     } else {
       // Create the view if it doesn't exist.
-      catalog.createTable(prepareTable(sparkSession, aliasedPlan), ignoreIfExists = false)
+      catalog.createTable(prepareTable(sparkSession, aliasedPlan, analyzedPlan),
+        ignoreIfExists = false)
     }
     Seq.empty[Row]
   }
@@ -212,14 +213,23 @@ case class CreateViewCommand(
    * Returns a [[CatalogTable]] that can be used to save in the catalog. Generate the view-specific
    * properties(e.g. view default database, view query output column names) and store them as
    * properties in the CatalogTable, and also creates the proper schema for the view.
+   *
+   * @param session the spark session.
+   * @param aliasedPlan if `userSpecifiedColumns` is defined, the aliased plan outputs the user
+   *                    specified columns, else it is the same as the `analyzedPlan`.
+   * @param analyzedPlan the analyzed logical plan that represents the child of a view.
+   * @return a CatalogTable that can be used to save in the catalog.
    */
-  private def prepareTable(session: SparkSession, aliasedPlan: LogicalPlan): CatalogTable = {
+  private def prepareTable(
+      session: SparkSession,
+      aliasedPlan: LogicalPlan,
+      analyzedPlan: LogicalPlan): CatalogTable = {
     if (originalText.isEmpty) {
       throw new AnalysisException(
         "It is not allowed to create a persisted view from the Dataset API")
     }
 
-    val newProperties = generateViewProperties(properties, session, originalText.get)
+    val newProperties = generateViewProperties(properties, session, analyzedPlan)
 
     CatalogTable(
       identifier = name,
@@ -276,7 +286,7 @@ case class AlterViewAsCommand(
       throw new AnalysisException(s"${viewMeta.identifier} is not a view.")
     }
 
-    val newProperties = generateViewProperties(viewMeta.properties, session, originalText)
+    val newProperties = generateViewProperties(viewMeta.properties, session, analyzedPlan)
 
     val updatedViewMeta = viewMeta.copy(
       schema = analyzedPlan.schema,
@@ -332,30 +342,17 @@ object ViewHelper {
    *
    * @param properties the `properties` in CatalogTable.
    * @param session the spark session.
-   * @param viewText the query string used to create the child plan on view resolution.
+   * @param analyzedPlan the analyzed logical plan that represents the child of a view.
    * @return new view properties including view default database and query column names properties.
    */
   def generateViewProperties(
       properties: Map[String, String],
       session: SparkSession,
-      viewText: String): Map[String, String] = {
-    // Try to analyze the viewText, throw an AnalysisException if the query is invalid.
-    val queryPlan = try {
-      val unresolvedPlan = session.sessionState.sqlParser.parsePlan(viewText)
-      val resolvedPlan = session.sessionState.analyzer.execute(unresolvedPlan)
-      session.sessionState.analyzer.checkAnalysis(resolvedPlan)
-
-      resolvedPlan
-    } catch {
-      case e: AnalysisException =>
-        throw new AnalysisException(s"Failed to analyze the view query SQL: $viewText",
-          cause = Some(e))
-    }
-
+      analyzedPlan: LogicalPlan): Map[String, String] = {
     // Generate the query column names, throw an AnalysisException if there exists duplicate column
     // names.
-    val queryOutput = queryPlan.schema.fieldNames
-    assert(queryOutput.toSet.size == queryOutput.size,
+    val queryOutput = analyzedPlan.schema.fieldNames
+    assert(queryOutput.distinct.size == queryOutput.size,
       s"The view output ${queryOutput.mkString("(", ",", ")")} contains duplicate column name.")
 
     // Generate the view default database name.