[SPARK-15047][SQL] Cleanup SQL Parser

## What changes were proposed in this pull request?
This PR addresses a few minor issues in SQL parser:

- Removes some unused rules and keywords in the grammar.
- Removes code path for fallback SQL parsing (was needed for Hive native parsing).
- Use `UnresolvedGenerator` instead of hard-coding `Explode` & `JsonTuple`.
- Adds a more generic way of creating error messages for unsupported Hive features.
- Use `visitFunctionName` as much as possible.
- Interpret a `CatalogColumn`'s `DataType` directly instead of parsing it again.

## How was this patch tested?
Existing tests.

Author: Herman van Hovell <hvanhovell@questtec.nl>

Closes #12826 from hvanhovell/SPARK-15047.

1 files changed, 9 insertions, 6 deletions

diff --git a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/PlanParserSuite.scala b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/PlanParserSuite.scala
index 5e896a33bd..b7af2ceda6 100644
--- a/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/PlanParserSuite.scala
+++ b/sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/PlanParserSuite.scala
@@ -53,7 +53,7 @@ class PlanParserSuite extends PlanTest {
     assertEqual("show functions foo", ShowFunctions(None, Some("foo")))
     assertEqual("show functions foo.bar", ShowFunctions(Some("foo"), Some("bar")))
     assertEqual("show functions 'foo\\\\.*'", ShowFunctions(None, Some("foo\\.*")))
-    intercept("show functions foo.bar.baz", "SHOW FUNCTIONS unsupported name")
+    intercept("show functions foo.bar.baz", "Unsupported function name")
   }
 
   test("describe function") {
@@ -263,11 +263,14 @@ class PlanParserSuite extends PlanTest {
   }
 
   test("lateral view") {
+    val explode = UnresolvedGenerator(FunctionIdentifier("explode"), Seq('x))
+    val jsonTuple = UnresolvedGenerator(FunctionIdentifier("json_tuple"), Seq('x, 'y))
+
     // Single lateral view
     assertEqual(
       "select * from t lateral view explode(x) expl as x",
       table("t")
-        .generate(Explode('x), join = true, outer = false, Some("expl"), Seq("x"))
+        .generate(explode, join = true, outer = false, Some("expl"), Seq("x"))
         .select(star()))
 
     // Multiple lateral views
@@ -277,12 +280,12 @@ class PlanParserSuite extends PlanTest {
         |lateral view explode(x) expl
         |lateral view outer json_tuple(x, y) jtup q, z""".stripMargin,
       table("t")
-        .generate(Explode('x), join = true, outer = false, Some("expl"), Seq.empty)
-        .generate(JsonTuple(Seq('x, 'y)), join = true, outer = true, Some("jtup"), Seq("q", "z"))
+        .generate(explode, join = true, outer = false, Some("expl"), Seq.empty)
+        .generate(jsonTuple, join = true, outer = true, Some("jtup"), Seq("q", "z"))
         .select(star()))
 
     // Multi-Insert lateral views.
-    val from = table("t1").generate(Explode('x), join = true, outer = false, Some("expl"), Seq("x"))
+    val from = table("t1").generate(explode, join = true, outer = false, Some("expl"), Seq("x"))
     assertEqual(
       """from t1
         |lateral view explode(x) expl as x
@@ -294,7 +297,7 @@ class PlanParserSuite extends PlanTest {
         |where s < 10
       """.stripMargin,
       Union(from
-        .generate(JsonTuple(Seq('x, 'y)), join = true, outer = false, Some("jtup"), Seq("q", "z"))
+        .generate(jsonTuple, join = true, outer = false, Some("jtup"), Seq("q", "z"))
         .select(star())
         .insertInto("t2"),
         from.where('s < 10).select(star()).insertInto("t3")))