[SPARK-17150][SQL] Support SQL generation for inline tables

## What changes were proposed in this pull request?
This patch adds support for SQL generation for inline tables. With this, it would be possible to create a view that depends on inline tables.

## How was this patch tested?
Added a test case in LogicalPlanToSQLSuite.

Author: petermaxlee <petermaxlee@gmail.com>

Closes #14709 from petermaxlee/SPARK-17150.

1 files changed, 15 insertions, 2 deletions

diff --git a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LocalRelation.scala b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LocalRelation.scala
index 9d64f35efc..890865d177 100644
--- a/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LocalRelation.scala
+++ b/sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/plans/logical/LocalRelation.scala
@@ -18,8 +18,9 @@
 package org.apache.spark.sql.catalyst.plans.logical
 
 import org.apache.spark.sql.Row
-import org.apache.spark.sql.catalyst.{analysis, CatalystTypeConverters, InternalRow}
-import org.apache.spark.sql.catalyst.expressions.Attribute
+import org.apache.spark.sql.catalyst.{CatalystTypeConverters, InternalRow}
+import org.apache.spark.sql.catalyst.analysis
+import org.apache.spark.sql.catalyst.expressions.{Attribute, Literal}
 import org.apache.spark.sql.types.{StructField, StructType}
 
 object LocalRelation {
@@ -75,4 +76,16 @@ case class LocalRelation(output: Seq[Attribute], data: Seq[InternalRow] = Nil)
 
   override lazy val statistics =
     Statistics(sizeInBytes = output.map(_.dataType.defaultSize).sum * data.length)
+
+  def toSQL(inlineTableName: String): String = {
+    require(data.nonEmpty)
+    val types = output.map(_.dataType)
+    val rows = data.map { row =>
+      val cells = row.toSeq(types).zip(types).map { case (v, tpe) => Literal(v, tpe).sql }
+      cells.mkString("(", ", ", ")")
+    }
+    "VALUES " + rows.mkString(", ") +
+      " AS " + inlineTableName +
+      output.map(_.name).mkString("(", ", ", ")")
+  }
 }