[SPARK-20145] Fix range case insensitive bug in SQL

## What changes were proposed in this pull request?
Range in SQL should be case insensitive

## How was this patch tested?
unit test

Author: samelamin <hussam.elamin@gmail.com>
Author: samelamin <sam_elamin@discovery.com>

Closes #17487 from samelamin/SPARK-20145.

2 files changed, 25 insertions, 1 deletions

diff --git a/sql/core/src/test/resources/sql-tests/inputs/table-valued-functions.sql b/sql/core/src/test/resources/sql-tests/inputs/table-valued-functions.sql
index 2e6dcd538b..d0d2df7b24 100644
--- a/sql/core/src/test/resources/sql-tests/inputs/table-valued-functions.sql
+++ b/sql/core/src/test/resources/sql-tests/inputs/table-valued-functions.sql
@@ -18,3 +18,9 @@ select * from range(1, 1, 1, 1, 1);
 
 -- range call with null
 select * from range(1, null);
+
+-- range call with a mixed-case function name
+select * from RaNgE(2);
+
+-- Explain
+EXPLAIN select * from RaNgE(2);
diff --git a/sql/core/src/test/resources/sql-tests/results/table-valued-functions.sql.out b/sql/core/src/test/resources/sql-tests/results/table-valued-functions.sql.out
index d769bcef0a..acd4ecf146 100644
--- a/sql/core/src/test/resources/sql-tests/results/table-valued-functions.sql.out
+++ b/sql/core/src/test/resources/sql-tests/results/table-valued-functions.sql.out
@@ -1,5 +1,5 @@
 -- Automatically generated by SQLQueryTestSuite
--- Number of queries: 7
+-- Number of queries: 9
 
 
 -- !query 0
@@ -85,3 +85,21 @@ struct<>
 -- !query 6 output
 java.lang.IllegalArgumentException
 Invalid arguments for resolved function: 1, null
+
+
+-- !query 7
+select * from RaNgE(2)
+-- !query 7 schema
+struct<id:bigint>
+-- !query 7 output
+0
+1
+
+
+-- !query 8
+EXPLAIN select * from RaNgE(2)
+-- !query 8 schema
+struct<plan:string>
+-- !query 8 output
+== Physical Plan ==
+*Range (0, 2, step=1, splits=None)